20: 20, 40, 60, 80, 100, 120, 140, 160, 180, 200
14: 14, 28, 42, 56, 70, 84, 98, 112, 126, 140
140 is the smallest number they have in common.
Answer:
4
Step-by-step explanation:
Use simultaneous equations:
2x + 7 = x^2 + 8x - 9
7 = x^2 + 6x - 9
16 = x^2 + 6x
+ or - 4 = 7x
answer is
-4/7 or 4/7
