Junior 3 Mathematics One dimensional quadratic equation application problems

Since ac squared = bc times ab, x squared = 1-x solution yields the value of x (take a positive value, the length must be positive).

Then ac ab=the value of x (answer -1 + 5 under the root number 2).

bc=ab-ac

Substitution. ac^2=（ab-ac）ab

ac^2=ab^

Also divide by ab 2

Let ac ab=a

Substituting yields: a 2 = 1-a

a = minus 1 plus minus the root number 5 and divide by 2 (sorry, I won't play the root number) to remove a root that does not match the actual root (the negative one).

ac+bc=ab;ac*ac=bc*ab bc=1-x;bc=x*x gives x*x+x-1=0 and solves the value of x, ac ab=x 1, i.e. (-1+ 5) 2 (rounding off the negative value).

Solution: From the problem, we can see that AC 2=BC*AB can be transformed into: BC AC=AC AB Let AB=1, AC=X, then CB=1-X, and bring it into the above equation to obtain:

1-x) x=x1 i.e. x2=1-x solution equation: x 2 + x = 1

x^2+x+(1/2)^2=1+1/4

Solution x ( 5-1) 2

Bringing x into the original equation yields: 1-( 5 1) 2 ( 5 1) 2 =( 5 1) 2

We have a chicken farm with a length x width and a width of y, if the long side of the chicken farm is against the wall.

x+2y=35

xy=150

Substitute x=35-2y into xy=150

35-2y）y=150

2y²+35y-150=0

2y²-35y+150=0

y-10)(2y-15)=0

y=10 y=

x=15 x=20

The chicken farm is 15 long and 10 wide, or 20 long and wide (the long side of the chicken farm is against the wall!). If the short side of the chicken farm is against the wall.

Solution. Length=10 or.

Width = 15 or 20

Because the length is greater than the width, this situation has to be discarded.

The length is 20 and the width is.

The length of the chicken farm is xm and the width is ym.

x+2y=35

x*y=150

y=10 or x=15 or 20

Because x>=20

So the length is 20 and the width is.

The length is 15 m and the width is 10 m

The length of the chicken farm is xm and the width is ym.

x+2y=35

x*y=150

If the length of the chicken farm is xm, the width of the chicken farm is 35-x 2

x*(35-x/2)=150

35x-x^2/2=150

35x-x^2=300

x1=20 x2=15

So the length is 20 and the width is.

Because a is greater than or equal to 20

So the length is 15 and the width is 10 rounded.

Suppose the average monthly growth rate of print runs is x.

50+50(1+x)+50(1+x)²=

50+50+50x+50+100x+50x²=50x²+150x+150=

x²+3x+3=

x+x+x=A:.

Hello! Let the average growth rate be x to obtain the equation.

50+50(1+x)+50(1+x)^2=50+50+50x+50+100x+50x^2=150+150x+50x^2=

50x^2+150x=

50(x^2+3x)=

50(x^2+3x)=31/2

x^2+3x)=31/100

x+3/2)^2=31/100+(3/2)^2(x+3/2)^2=256/100

x+3/2)^2=(16/10)^2

x+3/2=16/10

x=1/10=10%

So the growth rate is 10%.

Let the average growth rate be x to obtain the equation.

50+50(1+x)+50(1+x)^2=

If the average monthly growth rate is a, then 50*[1+(1+a)+(1+a) 2]=, the solution is: a=10%.

Solution: Let the average monthly growth rate of the monthly printing volume of this kind of book be x, and according to the title, the equation can be listed 50 + 50 (1 + x) + 50 (1 + x) =

Simplifying x + solution to this equation yields.

x1 = i.e. 10%), x2 = does not meet the requirements, rounded off) i.e. the average monthly growth rate of the print run of this type of book is 10%.

Let the average growth rate be x, then 50+50(1+x)+50(1+x) 2=

Average monthly growth rate x

50 + 50 (1 + x) + 50 (1 + x) 2 = left and right multiplied by 2

100x^2+300x-1=0

The bottom edge is 16, the waist is 10, and the area is 48

x*(18-x)=32

The solution yields: x=2 or 16

There are x people.

Each person of x shakes hands with other (x-1) individuals, and each person feels that they have shaken (x-1) times, for a total of x*(x-1) = (x 2-1) times.

Each is counted as repeated, and in fact the grip of (x 2-x) 2 times is made up of (x 2-x) 2=10

We get x 2-x-20=0, x-5)*(x+4)=0, so x=5 or -4 (rounded).

A: There are 5 people in total.

Answer the first question, and draw inferences from others, the same reason.

Set up x purchases, priced at y yuan.

There are two equations, one is that pricing determines the amount sold, and the other is that profit is equal to the selling price minus cost. You have to find these two equations from the question.

y-50）/1）*10=200-x

x*y=2000

Solution-available.