The Sum Of Two Numbers Is 90. The Larger Number Is Nine Times The Smaller Number. What Are The Numbers?

The sum of two numbers is 90. The larger number is nine times the smaller number. What are the numbers?

 

Answer

The numbers are 81 and 9

Let x = larger number

y = the smaller number

Equation1: x + y = 90

Equation2: x = 9y

Just use the substitution method

x + y = 90

9y + y = 90

10y = 90

y = 9

x = 9y

x = 9(9)

x = 81

Checking

x = 9y

81 = 9(9)

81 = 81 true

x + y = 90

81 + 9 = 90

90 = 90 true