Directions: Simplify the following monomials (if possible). 13.) 13y² + 9y + 4y² - 31y
14.) 10m²n + 7mn² - m²n
15.) Find the sum of 16y² and -5y²
16.) Find the difference of 10x²y and 2x²y

ANYONE PLEASE HELP ME I REALLY NEED THE ANSWER NOW BECAUSE I HAVE TO PASS THIS TOMORROW AT MY 1ST CLASS:( EVERYONE HELP ME:(
I'LL MARK YOU AS THE BRAINLIEST!​

What is the perimeter, p, of a rectangle that has a length of x + 8 and a width of y − 1? p = 2x + 2y + 18 p = 2x + 2y + 14 p = x + y − 9 p = x + y + 7

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.

52 cm radius = diameter = area = circumference = circumfer