Question

Hallie can use the equation p = 4l + 4w + 4h to determine the sum of the lengths of the edges of a rectangular prism. She begins to solve the equation for h but runs out of time. Her partial work is shown below:

p = 4l + 4w + 4h
2. StartFraction p Over 4 EndFraction equals StartFraction 4 l plus 4 w plus 4 h Over 4.
3. StartFraction p Over 4 EndFraction equals l plus w plus h. = l + w + h
h = 4. h equals StartFraction p Over 4 EndFraction minus blank. –
Which expression should follow the subtraction in Hallie’s equation?

(l + w)
(l – w)
left-parenthesis StartFraction l plus w Over 4 right-parenthesis.
left-parenthesis StartFraction l plus w Over 4 EndFraction right-parenthesis.

Answer 1

(l + w)

Because p/4 = l + w + h, subtract l and w from both sides: h = p/4 − l − w = p/4 − (l + w).