Answer:
C
Step-by-step explanation:
49x² + 28xy + 4y² ← is a perfect square of the form
(ax + by)² = a²x² + 2abxy + b²y²
49 = 7² ⇒ a = 7 and 4 = 2² ⇒ b = 2
2ab = 2 × 7 × 2 = 28
Hence
49x² + 28xy + 4y² = (7x + 2y)²
with factor 7x + 2y ⇒ C
Multiply each hourly rate by x ( time to complete the work) add it to the service call for each and then set the equations equal:
50 + 40x = 30 +45x
Subtract 30 from both sides:
20 + 40x = 45x
Subtract 40x from both sides:
20 = 5x
Divide both sides by 5
x = 4
The length is 4 hours.
What is the question pls so I might be able to help
He needs 4 boxes :)
Dozen= 12
48 ÷12=4
