Imagine a 'U' shape
sides are x legnth
base is b legnth
2x+b=25
area is height times base=xb
xb=50
2x+b=25
solve
minus 2x both sides
b=25-2x
sub for b
x(25-2x)=50
25x-2x^2=50
times -1 both sides
2x^2-25x=-50
add 50 both sides
2x^2-25x+50=0
use quadratic formula or something
x=2.5 or 10
A is the answer
Answer:
2
Step-by-step explanation:
24/12 = 2
Answer: the 4th boy is 11
Step-by-step explanation:
Let's denote the age of the boys as: x₁, x₂, x₃, x₄.
Then,

Multiply both parts of the equation by denoting by 3:
x₁+x₂+x₃=15(3)
x₁+x₂+x₃=45
Hence,

Multiply both parts of the equation by denoting by 4:
45+x₄=14(4)
45+x₄=56
45+x₄-45=56-45
x₄=11
Answer:

Step-by-step explanation:
Given

![(x + 7) * (\ ) = [\ ]](https://tex.z-dn.net/?f=%28x%20%2B%207%29%20%2A%20%28%5C%20%29%20%3D%20%5B%5C%20%5D)
Required
Complete the blanks
We have:

Rewrite as:

Cross multiply

240+140+168+96
380+264
644 cm^2