Junior high school math review materials, everyone help me! High Score .

What version of the textbook is it?

The focus should be on unary equations, binary equations, inequalities, and geometry.

Inequality. Binary and ternary linear equations. Geometry. Triangle!!

1.If 2x-y=5 is known, then 5-6x+3y=5-3(2x-y)=5-3*5=-10

2.If we know that an algebraic formula adds -2x and the nickname is mistakenly seen as subtracting -2x, the result is 3x -2x-1, then the correct result is 3x -6x-1

3.The unit price of a book is X yuan, and the postage is 10% of the book price, and if you buy a book like Y, the purchase price should be n yuan, then n = a（1+10%）xy

Choose A4If a+b=3ab, then the key is 2a+2b-ab a+b+2ab and is worth the value of the deuterium

2(a+b)-ab]/[a+b)+2ab]

6ab-ab)/(3ab+2ab)

5ab/5ab

5.When 2a+3b-1=0, 8-4a-6b=6+2-4a-6b=6-(2a+3b-1)=6-0=6

6.If it is known that a=5a-3b=-6a+4b, then a-b= (5a-3b)-(6a+4b)=5a-3b+6a-4b=11a-7b

First 3 = 9.

The single digits of 3 to the nth power are 3 9 7 1 3 9 7 1 ....... A cycle every four times.

3+9+7+1 single digit is 0

That is, 3 + 3 +....The single digit of 3 is 0 and the 3 digit is the first digit of the cycle, which is 3.

3 digits are 9.

The answer in the question is the single digit of 3+9 of the canopy slip, which is 2.

We can use modulo arithmetic to calculate the last digit of 3 + 3 +3 +3 +3.

First, we can find that for any rock jujube integer n,3 n 3 (n mod 4 + 4) (mod 10).

This is a guess because, any multiple of 4 n, 3 n 3 4 81 (mod 10), therefore, the last digit of 3 n is always 1.

For the other n, we can use recursion to figure out the last digit of 3 n:

Thus, for any integer n, the last digit of 3 n is either or 9.

Therefore, the last digit of 3 + 3 +3 + 3 + 3 is (1 + 9 + 7 + 1 + 9) (mod 10) = 1 + 9 + 7 + 1 + 9 = 107 (mod 10) =7.

Solution: (1) There are 4 possibilities. 1. Breakfast + 2 yuan for 1 serving (Chinese food) + 2 yuan for 1 serving (dinner)**: 1 + 2 + 2 = 5 yuan.

2. Breakfast + 2 yuan for 1 serving (lunch) + 3 yuan for 1 serving (dinner)**: 1 + 2 + 3 = 6 yuan.

3. Breakfast + 3 yuan for 2 servings (Chinese food) + 2 yuan for one (dinner)**: 1 + 3 + 2 = 6 yuan.

4. Breakfast + 3 yuan for 2 (lunch) + 3 yuan for one (dinner)**: 1 + 3 + 3 = 7 yuan.

2) Take two kinds of **, set the first meal** for x days, and the second meal** for y days, that is, x+y=108, 5x+6y=600

The solution is x=48 and y=60

So, the first meal** is 48 days, and the second meal** is 60 days.

1) Morning, noon, and evening are 1 2 2, 1 2 3, 1 3 2, 1 3 3, 1 2, 1 3

You take 2 equations from (1) and then list the equations x+y=108 x***+y***=600

The bounty should be around 100 before anyone answers.

2 -1 c b a 19 or -19 or -5 or 5 is there a problem? 1 1 or 3 or 5 n+1?? 98 7

101011 = 1 (2 to the 5th power) + 0 (2 to the 4th power) + 1 (2 to the 3rd power) + 0 (2 to the 2nd power) + 1 (2 to the 1st power) + 1 (2 to the 0th power) = 43

∠c+∠a=2∠b

a＋∠b＋∠c=3∠b

So b=60°

So c+ a=120°

And because c- a=80°

The solution yields a=20° and c=100°

The triangle has an inner angle and 180 so a b c = 180° because c a 2 b

3∠b=180° ∠b =60°

c＋∠a=120°

c－∠a=80°

2∠c=180

c=90180-∠b＋∠c=180-90-60=30

Let's do it with the column equation, let the angle a be x, then the angle c is x+80 degrees, so the angle c plus the angle a is 2x+80 degrees, so the angle b is x+40 degrees, so the angle a plus the angle b plus the angle c is 2x+80+x+40=180 degrees, so x=20 degrees, so the angle a is 20 degrees, the angle c is 100 degrees, and the angle b is 60 degrees.

Knowing that abc c a+ b=180, and because c a 2 b, c a 80° can be calculated as a=20° b=60° c=100°

Solution C A2 B C A 80°

a+∠b+∠c=180° ③

Get C B+40°

get a b-40°

Put , substitute

Get b 60°

Substituting b 60° into a 20° yields a 20°

Substituting a 20° into c 100° is obtained

So a 20°, b 60°, c 100°

This problem is mainly used to use the sum of the inner angles of the triangle is 180, bring it into your first formula, and you get it

Let a=a

then c=80°+a

2∠b=∠c+∠a=80+a+a

So a+ b+ c=a+(80+a+a) 2+80+a=180 (the sum of the inner angles of the triangle is equal to 180°).

The solution is a=20

So a 20°, b 60°, c 100°

a+b+c=180°, c+a=2b, so 2b+b=180°, i.e. b=60°

And because c+a=120°, c-a=80°, c=100°, a=20°

Because in ABC C C a b = 180° and c a 2 b, 2 b b = 180°

So b=60°

c a 120°(1).

c－∠a＝80° (2)

So (1)+(2) is 2 c=200°

So c=100°

a=20°

It's simple:

c＋∠a＝2∠b；

c a + b = 180 degrees.

Then 3 b = 180 degrees, b = 60 degrees.

c a=120 degrees, c a 80°, then: c=100 degrees, a 20 degrees.

∠c＋∠a＝2∠b

And because c plus b+a=180

So 3b=180, so b=60

So a=20

b=60c=100ok?

Solution: Let c=x°, a=y°.

x+y=2(180-x-y)

x-y=80

Solution, get: x=100, y=20

So the angle c = 100°, a = 20°, b = 60°

B60C100A20 Column a system of equations to solve it, thank you.

∠c＋∠a＝2∠b

And because c plus b+a=180

So 3b=180, so b=60

So a=20

b=60c=100

I don't understand what you're asking there.

Bonus points! （1）∵∠aoe=100°

eob=80°

The quadrilateral OEFG is derived from the quadrilateral OGCB folded along the OG EOG= GOB=1 2 EOB=40°(2), which can be obtained from question (1).

180°-x°）=2y°

Simplified to y° = 90°-1 2x°

or x°=180°-2y°).

or x°+2y°=180°).

Strongly ask for a plus!!

1.If aoe=180, then eog=o

2.If aoe=x, eog=y, then the formula is x+2y=180

-6x 2y m and 1 3x n-1y 3 What is the relationship between m and the following 3 and the previous number? Is n-1 a coefficient to the nth power of y? The first term has m and the second term does not, so we can see that m is a constant 3

The same term, that is, the exponent of the same letter is the same, and in the two formulas, the exponent of x is the same, and the exponent of y is also the same. Sorry, the following questions are a bit confusing.