First, distribute 3a to (4a−1): 3a(4a−1)=3a(4a)−3a(1)=12a2−3a Next, distribute 2a to (a+3): 2a(a+3)=2a(a)+2a(3)=2a2+6a Then, distribute −5a to (2a−1): −5a(2a−1)=−5a(2a)−5a(−1)=−10a2+5a Now, combine the results:
12a2−3a+2a2+6a−10a2+5a Combine like terms:
(12a2+2a2−10a2)+(−3a+6a+5a)=(12+2−10)a2+(−3+6+5)a=4a2+8a