Answer:
x = -7
Explanation:
Solve for x:
5 - 4 x + 3 (3 x + 5) = -15
3 (3 x + 5) = 9 x + 15:
(9 x + 15) - 4 x + 5 = -15
Grouping like terms, 9 x - 4 x + 5 + 15 = (-4 x + 9 x) + (5 + 15):
((-4 x + 9 x) + (5 + 15)) = -15
9 x - 4 x = 5 x:
5 x + (5 + 15) = -15
5 + 15 = 20:
5 x + 20 = -15
Subtract 20 from both sides:
5 x + (20 - 20) = -20 - 15
20 - 20 = 0:
5 x = -20 - 15
-20 - 15 = -35:
5 x = -35
Divide both sides of 5 x = -35 by 5:
(5 x)/5 = (-35)/5
5/5 = 1:
x = (-35)/5
The gcd of -35 and 5 is 5, so (-35)/5 = (5 (-7))/(5×1) = 5/5×-7 = -7:
Answer: x = -7