The area of the model is 100.25in^2
So, letter D
Sorry for the bad handwriting but the answer is -23<3x
To determine the answer, we need to set up equations. We do this by doing mass balances. We let
x = A alloy 25% copper
y = B alloy 55% copper
Overall Mass balance:
x + y = 100
Copper mass balance:
.25x + .55y = .43(100) = 43
SOlving simultaneously, we get:
x = 99.67 kg 25% copper alloy
y = 0.33 kg 55% copper alloy
To find how many square feet her patch of lawn is, we need to find what the area of the lawn is. To find the area of a rectangle (which is what the patch of lawn is), we need to multiply length and width. The length of this rectangle is 10 feet and the width of this rectangle is 9 feet. To figure out what 10 * 9 is, we need to multiply all parts of 10 (10, and 0) by 9. 10 * 9 = 90, while 0 * 9 = 0. Adding them together, we get that the piece of lawn is 90 square feet.
