#### Answer

a = $\frac{25}{7}$

#### Work Step by Step

-4(a + 1) - 3a = -7(2a - 3)
Distribute:
-4a -4 - 3a = -14a + 21
Combine like terms:
-7a - 4 = -14a + 21
Add 14a to both sides:
7a - 4 = 21
Add 4 to both sides:
7a = 25
Divide both sides by 7:
a = $\frac{25}{7}$