Answer:
No
Step-by-step explanation:
Substitute 3 in for y
7y-12
7(3)-12
21-12
9
She is not correct, the correct answer would be 9
Do you mean half an hour because if she can paint 2/3 of each section in half an hour, it would take her 3 hours to paint all 9 sections. I hope this is correct.
I'm pretty sure 4/10=40/100
You are expected to know (-x)*(-x) = x^2 = (x)*(x) for any value of x.
With this in mind, you expect to be looking for squares in answer to your question. You will find them.
1) y² = 49 . . . . . . . 4th selection
2) y² = 16 . . . . . . . 3rd selection
You can add up all the equal terms:
So for x: 6x-4x = 2x
For y: 2y
For the numbers: 3+7=10