4a + 5 = 3(a - 7) + 2a
Start by distributing the 3 on the right side.
4a + 5 = 3 * a - 3 * 7 + 2a
4a + 5 = 3a - 21 + 2a
Now combine like terms on the right side. The like terms are 3a and 2a. They add up to 5a.
4a + 5 = 5a - 21
Subtract 5 from both sides.
4a = 5a - 26
Now subtract 5a from both sides.
-a = -26
Divide both sides by -1.
a = 26