8th grade math problems, well done scores

Solve the equation: 1[sqrt2-1] 2 or [-sqrt2-1] 2 or -1 2 3

No solution or -2 3 5No solution 6There is no solution sqrt5) or the opposite of the equation or 14 9

3 or -9 or -7 or -4 5 or -5 4 or 4 3 14-4 or -5 15-4 or 2 3

Applications:1(4k 1)*(4k 1)-4*2*(2k*k-1)>0 solution k>-9 8 The second question is that the formula is equal to 0 and the solution is k=-9 8 The third question is that the formula is less than 0 and the solution is k<-9 8 2

Let the shorter right-angled edge be x, then the other right-angled edge is x 1 x*x [x 1]*[x 1]=7*7 to get x=[sqrt97-1] 2 3Let the two numbers be x,y x-y=4, x*y=45, and x= or x= 4Let two squares have one side length x and one side length y

4x 4y=56,x*x y*y=100 to get x=6,y=8 or x=8,y=6 for the second question, just change the latter equation to equal 196 to solve x=0, y=14Three questions are the same. 5.

Let the annual growth rate be x 40 [1 x] * [1 x] = solution x = note sqrtx is the square root of x. Ask less next time!

Did you send all the exam questions? Classmates, others can only provide you with methods, is the answer useful, it's just a momentary excitement! Read more books, and if you have mastered things, that's the last word!

Draw the diagram, b'BC in the spike collapse AC is high, ACB'=∠acb ab'=ab by acb followed by acb'The area of the Zen finch is equal to that of the Kehe tribe, as evidenced by the early evidence.

Make use of triangle congruence proofs.

acb≌△acb‘

ab=ab‘

1. Real numbers or silver.

2. x is equal to 0

3, x 4, there is a problem with the question, is it 2 + 1x of 3, the answer is x 6

.If the temperature of type A air conditioner is increased by 1°C to save electricity by x degrees per day, then the temperature of type B air conditioner is increased by 1°C to save electricity (x-27) degrees per day. From the meaning of the title:

x+(x-27) solution obtains x=207, so only after the temperature is raised by 1 °C, the two air conditioners save 207 + (207-27) = 387 degrees per day

1) Set up workers for each set of children's clothing enterprises should be rewarded at least x yuan, from the title: 200 + 150 60% x 450 solution x that is, 2 yuan 7 jiao 8 points.

2) Set Xiaozhang should process at least a set of children's clothing in June, which is obtained from the title: 200 + 5A 1200 to get a 200

The number of sets of children's clothing processed by the most unskilled workers = 150 * 60% = 90 sets of workers, and the enterprise should reward at least x yuan for every 1 set of children's clothing processed.

200+90x》450

x >> Workers should be rewarded at least 1 yuan for each set of children's clothing processed.

Xiao Zhang should process at least Y sets of children's clothing in June.

200+5y》1200

Y》200 sheets should be processed in June with at least 200 sets of children's clothing.

Solution 1) be=de

Proof: Acc= dac, bca= dca, and ac is a common edge.

then abc adc asa

then bc=dc

bca= dca, and ce is the common side.

Then BCE DCE (SAS).

So be=de

2) There is still be=de that holds.

A] If E is on the right extension of AC, the complementary angle is known by BCA= DCA BCE= DCE, and BC=DC, where CE is the common edge.

Then BCE DCE

then be=de

b] If E is on the left extension of AC, BCA= DCA, BC=DC, and CE is the common side.

bce≌⊿dce

then be=de

In summary, be=de is still true.

Good luck with your studies (*.)

(1) AC deuces bad=> bac= dac; AC deuces BCD=> BCA= DCA; ac=ac, so bcd is equal to dca=>bc=dc;

CE=CE, BCE= DCE, and the corner edge BCE is all equal to DCE=>BE=DE

2) From (1), BCD is equal to DCA=>AB=AD;

AC deuces bad=> bac= dac; ae=ae;

Corner edge triangle congruence, be=de

BAC DAC can be certified with ASA

ab=ad, which can be demonstrated by SAS, bae dae

be=de2) is the same as (1).

It's been a long time since I've done this kind ......of question, and I miss it

(1) Equal proband ABC adc because ( BAC DAC AC=AC BCA= DCA).

So cb=cd and cbe cde because ce=ce, so be=de

2) It is also established that the law is modeled on.

(1) As can be seen from the figure, B departs from city B 1 hour after A's departure (2) and meets, B uses 2 and 7/9 minus 1 1 and 7/9 hours (3) Let the functional relationship of A be s=kt+b

Substituting (0,80) (2 and 7/9,40) into the system of column equations results in k = minus 72/5 b = 80

Let the function relation of A be s=kt+b

Substituting (1,0) (2 and 7,40/9) into the system of column equations results in k = 45/2 b = negative 45/2

4) A is 72/5 B is 45/2 (5) and arrives at B first.

(1) As can be seen from the diagram, B departs from City B 1 hour after A.

2) When they meet, B uses 25/9 minus 1 16/9 hours (3) The relation of A is s=kt+b

Substituting (0,80) (2 and 7,40/9) into the system of equations k = minus 72/5

b=80 and the function of A is s=kt+b

Substituting (1,0) (25,40/9) into the system of column equations results in k = 45/2 b = negative 45/2

4) A is 72/5 B is 45/2 (5) B arrives first.

(1) As can be seen from the image, B departed from City B 1 hour after A's departure.

2) From the image, it can be seen that 16-9 hours A and B meet.

3) S A = 80-72 5t

s B = (4) A's speed is 72 5 km/h.

B's velocity in kilometers.

5) The time taken by A is 50 9 hours, and the time taken by B is (32 9+1) hours, so B arrives at the destination first.

Hope you are satisfied.

The first square is equal to 16+4 root number (with number 6-2, root number 5), and root number (6-2 root number 5) is equal to root number 5-1

Therefore, the upper sock style is equal to 12 + 4 root number 5

The re-opening is equal to the root number 10 + the root number 2

Square first and then open the root number.

5. There is no square, so it is best to combine and then open the square, and it is best to operate with the root number.

Just look at the median, the median of Class A is 104, that is, the 14th place is 104 points, and the 14th place in Class B is 106 points. It shows that there are at least 14 people in class B who meet the 105 standards, and there are not so many in class A, so the excellent rate of class B is high.

If there is something you don't understand, ask again, I wish you to learn and make progress and go to the next level! (

The excellent rate of the first is small.

The median of B is 106, which means that half of B is above 106, (including 106), that is, at least half of B is excellent. The median of A is less than 105, even if there is only one person with a score of 104, and the others above 104 are all excellent, and the excellent rate is less than half, so, fill in the <.

According to the median of class A and B, the number of excellent students in class B can be preliminarily judged to be 14, and the number of excellent students in class A is 13

Therefore, fill in

B's excellent rate is greater than A's.

97x27>96x27 So A's total score is more, and because B's median score is more, B's score of 105 or more is more than A's, then B's excellent rate is greater than A's.

Class A is smaller than Class B. Because the two classes have the same number of people. The median of class B is 106, and the median of class A is 104 (the median is the number of people in the middle), which means that the number of people skipping rope more than 105 in class B is more than that of class A. Therefore, the excellent rate of skipping rope in class B is high.

The median of class A is 104, which means that the fourteenth student jumped 104 times per minute, so there are 13 students who jumped 105. The excellent rate of Class A is 13 divided by 27 times % = 48%.

The median number of class B is 106, which means that the fourteenth student jumped 106 times per minute, so there are 15 students who jump 105. Class B has an excellent rate of 15 divided by 27 times % = 56%.