Question

a=4b-15 a and b have to add up to 90 so whats the answer?

Answer 1

Step-by-step explanation:

a+b=90

a = 90-b

Therefore, 90-b = 4b - 15

90+15 = 4b + b

105 = 5b

b = 21

substitute b in and get, 4(21)-15 = 69

a=69 and b=21