Answer:
21
Step-by-step explanation:
we have
5x+4=2x+9
5x-2x=9+4
3x=13
x=13/3
Answer: C.
Explanation: X= -7
Answer: (-5x2 - 8x + 7) - (5x2 - 4)
= -5x2 - 8x + 7 - 5x2 + 4
= -5x2 - 5x2 - 8x + 7 + 4
= -10x2 – 8x + 11
Answer: = (-5x2 - 8x + 7) - (5x2 - 4)