Answer:
Each side is 35.78 mm
Step-by-step explanation:
A square would have 4 equal sides. Since area of a square is x^2, where x is one side, we can write:
x^2 = 1280
x = 35.78 mm
Each side is 35.78 mm
A and d seem correct to me.
b and c are definitely wrong.
Amy: x skirts
Betty: 2x skirts
Carol: (2x) + 7 skirts
If Amy has 18 less than Carol, than Carol's equation minus 18 equals Amy's equation:
[(2x) + 7] - 18 = x
+18 +18
(2x) + 7 = x + 18
- 7 -7
2x = x + 11
-x -x
x = 11
Input the solution for x into the girls equation to double check.
Amy: 11
Betty: 2(x)
2(11)
=22
Carol: (2x) + 7
22 + 7
=29
Does Amy have 18 less than Carol?
Carol - Amy = 18
29 - 11 = 18
18 = 18
the problem is solved
3x - (2x + 8) = -6
3x -2x - 8 = -6
x - 8 = -6
x - 8 + 8 = -6 + 8
x = 2