(Solving similar triangles!)
Can someone please help and explain thoroughly on how to do it??

y=22.5

Step-by-step explanation:

Ok since the triangles are similar, the ratio of the length of the lines will be equal.

DEF=ABC

So BA equals to ED (1,2,3=1,2,3 so D=A E=B F=C)

To get one of the ratios divide the line you are looking for with one of the other ones of the same triangle

37.5/20=1.875 <-- This is ED/DF which since the triangles are congruent, means that BA/AC should equal to 1.875 too

Since we already have AC, all we need is to solve

BA/12=1.875

Multiply both sides by 12

BA=22.5

And since BA and y are the same thing, y=22.5

susie has 7 apples

the polynomial is a perfect square trinomial of the form a^2-2ab+b^2:

option a. true

step-by-step explanation:

9x^2-12x+4

comparing with the form a^2-2ab+b^2

1.) a^2=9x^2

solving for a: square root both sides of the equation:

sqrt(a^2)=sqrt(9x^2)

a=sqrt(9) sqrt(x^2)

a=3x

2.) b^2=4

solving for b: square root both sides of the equation:

sqrt(b^2)=sqrt(4)

b=2

to be a perfet square trinomial 2ab must be equal to 12x. let's check:

2ab = 2 (3x) (2)

2ab = 12x

correct