For the volume of a rectangular prism (box-shape), all we have to do is multiply, length * width * height. We know from the text that the hole the construction company will be digging is 12 yards long, 7 yards wide, and 3 yards deep, so all we need to do to find the volume of the dirt removed in cubic yards is multiply, 12 * 7 * 3.
12 * 7 = 84
84 * 3 = 252
The construction company will have removed 252 cubic yards of dirt for the swimming pool. Hope that helped! =)
X - 6% y - 11% We need 10 liters of 8%. A) x + y = 10 B) .06x + .11y = (10 * .08) Multiplying equation A by -.06 A) -.06x + -.06y = -.6 Then adding this to B) B) .06x + .11y = (10 * .08) .05y = .2 y = 4 liters of 6% x = 6 liters of 11%