Answer:
The correct answer is not shown in your picture. You must get a = 60.
Step-by-step explanation:
(1/2)a + (2/3)b = 50
b = 30
(1/2)a + (2/3)(30) = 50
(1/2)a + 20 = 50
(1/2)a + 20 - 20 = 50 - 20
(1/2)a = 30
2 * (1/2)a = 2 * 30
a = 60
The correct answer is not shown in your picture. You must get a = 60.
Answer: 110 square inches.
Step-by-step explanation:
The volume of a rectangular box would be:

In this case, we know the volume, the length and the height, and we don't know the width, so we're going to isolate it:

Substituting the data:

This width is also the width of the top of the box, so the area of the top would be:

Answer:
56.5 inches
Step-by-step explanation:
You want to find the perimeter (or the length around the rectangle) to find much lace he needs. the formula for perimeter is 2L+2W=P. L being length, w being width and p being perimeter. Plug in the values for the equation and get 2(12.75)+2(15.5)=P. Multiply and get 25.5+31=56.5.