Divide 5 by 2 representing each box by the price. Which equals to $2.50 each box.
The LCM for 4 and 9 is 36
Step-by-step explanation:

• y2 → -1
• y1 → 5
• x1 → 4
• x2 → -3

The best step to do next is to add 80 to both sides of equation:
5 ( x² + 8 x ) + 80 = 14 + 80
and since 80 = 5 · 16
5 ( x² + 8 x + 16 ) = 94 Answer : B )
After that we will continue like this:
5 ( x + 4 )² = 94
( x + 4 )² = 18.8 ... etc