Answer:
a = -1
Step-by-step explanation:
Solve for a:
a + 2 = 4 a + 5
Subtract 4 a from both sides:
(a - 4 a) + 2 = (4 a - 4 a) + 5
a - 4 a = -3 a:
-3 a + 2 = (4 a - 4 a) + 5
4 a - 4 a = 0:
2 - 3 a = 5
Subtract 2 from both sides:
(2 - 2) - 3 a = 5 - 2
2 - 2 = 0:
-3 a = 5 - 2
5 - 2 = 3:
-3 a = 3
Divide both sides of -3 a = 3 by -3:
(-3 a)/(-3) = 3/(-3)
(-3)/(-3) = 1:
a = 3/(-3)
The gcd of 3 and -3 is 3, so 3/(-3) = (3×1)/(3 (-1)) = 3/3×1/(-1) = 1/(-1):
a = 1/(-1)
1/(-1) = -1:
Answer: a = -1
