3x + 11y = 4
2x + 6y = 0
I got
15/2, -5/4
The answer to your problem is that Marisol’s shadow would be 144 feet long
The answer is the letter c. 3
You have to find a common denominator 1st then add. So 16 is the common denominator the problem should be 2 7/16+1 14/16+8-16= 3 29/16 then you need to divide 29/16 you will have 4 13/16
Remark
I'm going to interpret this equation as
D = ut + kt² The only difference is the 2.
Solution
Subtract kt² from both sides.
D - kt² = ut Now divide by u on both sides.

The t's cancel out. on the right. You are left with u on the right.
