Answer:
a) 24
b) 63
c) 2
d) -2
Explanation:
you are supposed to try different numbers, but...
X-9 = 15 add 9 to both sides
X = 24
7x/9 = 49 multiply both sides by 9
7x = 441 divide by 7
x = 63
3(x + 6) = 24 divide both sides by 3
(x + 6) = 8 subtract 6 from both sides
X = 2
11x + 2 = -20 subtract 2 from both sides
11x = -22 divide both sides by 11
X = -2