A.

B.

Megan's solution isn't correct.
The first mistake: she subtracted 5x from the right-hand side of the equation, but added 5x to the left-hand side.
The second mistake: she divided the right-hand side of the equation by 11, but didn't divide the left-hand side.
The correct solution:
Answer:
$46
Step-by-step explanation:
Cost: 4p + 3c + 16
if p=3 and c=6 then,
4(3) + 3(6) +16
12+18+16
46 dollars spent
Answer:
<h2>Height (h) =54.6mm</h2>
Step-by-step explanation:
Given :
Base (b) = 7.7mm
Area (a) = 210.21mm^2
Height (h) = ?

"necessary"
It is not a "sufficient" condition. Another condition is that the figure be a plane quadrilateral.