D.
a.
b.
hope that helped
Combine like terms the solve. For example:
5x + 20x = 100
25x = 100
/25 = /25
x =4
It CAN'T equal 21, since 9+10=19
BUT, if the 9 was changed to like, 11 - Then it would = 21, or if the 10 was changed to a 12, it would make 21 also,
Hey Astute!
Solve: x^2 - 18x = -72
Solution:
x^2 − 18x − (−72) = −72 − (−72) (Subtract -72 from both sides of the equation)
x^2 − 18x + 72 = 0
(x − 6) (x − 12) = 0 (Factor left side)
x − 6 = 0 or x − 12 = 0 (factors have to equal 0)
6 - 6 = 0 or 12 - 12 = 0
Answer:
x = 6 or x = 12
Hope This Helps, Have a Great Day!