What is the value of a in the equation 5a - 10b = 45, when b = 3?

Plug 3 in

5a - 10 (3) = 45

5a - 30 = 45

Perform the opposite operation by adding 30 on both sides of the equation

5a = 75

Perform the opposite operation of dividing both sides of the equation by 5

5's cross out on the left

5/5=1

Result will be 15 on the right

75/5 = 15

a = 15

5a-10 * (3) = 45

5a=75

a=15

(b=3)