Answer:

Step-by-step explanation:
Perform the square of the binomial, combine like terms, and then write the remaining expression in decreasing order of powers of x:

Answer:
m∠P = 107º
Step-by-step explanation:
Since two sides are parallel this is a trapezoid
In a trapezoid, the angles on the same leg (called adjacent angles) are supplementary, meaning they add up to 180 degrees.
(7x + 31) + (21x - 19) = 180
combine like terms
28x + 12 = 180
Subtract 12 from both sides
28x = 168
Divide both sidees by 28
x = 6
m∠P = 21x - 19
m∠P = 21(6) - 19
m∠P = 107º
Subtract the original from the new to find the difference:
148 - 74 = 74
Now divide the new by the difference:
148 / 74 = 2
Multiply that by 100 to get the percentage:
2 x 100 = 200%
It was a 200% increase.
The answer will either be E or 38