Y=7 because there is no slope and the Y intercept is at 7.
When we factor out something, we divide the factor by the equation. For example if we were to factor 3 out of 6, It will be 3(2). We got this answer by dividing 3 and 6. Using this concept:
![\frac{-1}{4}[( \frac{-1}{2} / \frac{-1}{4}) - ( \frac{5}{4} y / \frac{-1}{4})]](https://tex.z-dn.net/?f=%20%5Cfrac%7B-1%7D%7B4%7D%5B%28%20%5Cfrac%7B-1%7D%7B2%7D%20%2F%20%5Cfrac%7B-1%7D%7B4%7D%29%20-%20%28%20%5Cfrac%7B5%7D%7B4%7D%20y%20%2F%20%20%5Cfrac%7B-1%7D%7B4%7D%29%5D%20%20)
Simplifying:

Hope this helps!
Just solve until the answers are the same
25 times x plus 30 for John
15 times x plus 50 for Mary
As far as the old dimensions of the photo are concerned,
Width of the photo = 3"
Length of the photo = 5"
New length of the photo = 7 inches
Let us assume the new width of the photo = x inches
Then
3/5 = x/7
5x = 7 * 3
5x = 21
x = 21/5
= 4.20 inches
So the correct option among all the options that are given in the question is the first option. I hope that the answer has come to your help.