Answer:
Step-by-step explanation:
area = ½×base×height
21 = ½(x+1)x
42 = (x+1)x
x² + x - 42 = 0
(x+7)(x-6) = 0
x = -7, 6
-7 is an extraneous solution, so x = 6
ANSWER
D. x=55
EXPLANATION
The given radical equation is

Add -3 to both sides


Square both sides.


Solve for x to get:

Answer:what are all the answers.sorry i cant see all the answers all i see is 80,and 160 degrees if there is a 360 degrees i would go with that one and my apologies if that answer was wrong.
Step-by-step explanation:
Answer: -4y + 4
Step-by-step explanation: 12 + 3y - 8 - 7y
12 + 3y + -8 + -7y
(3y + -7y) + (12 + -8)
= -4y + 4