joe's mountain bike weighs 7 pounds more than andy's. If their bikes weigh 45 pounds altogether, how much does joe's bike weigh? ( who is x? )

Answer 1

x = 7+ a

x+a= 45

7+a +a = 45

2a= 45-7 = 38

a =38/2= 19 lbs = Andy's bike weight

x = 19+7 = 26 lbs = Joe's bike weight

Joe's bike weight = Andy's bike weight +7 lbs

26=19+7

Joe & Andy's sum to 45

26+19 = 45