sum of two numbers 4 10

Question

The sum of two numbers is 86
If four times
the smaller number is subtracted from the larger? number, the result is 16  
Find the two numbers.

Answer 1

Let x = larger number, y = smaller number

 

x + y = 86

 

x - 4y = 16

 

Just solve these two equations in two unknowns x and y.

 

Subtract bottom equation from top equation and get

 

5y = 70

 

y = 14

 

Substitute y into either equation, say the top equation, and get

 

x + 14 = 86

 

x = 86 - 14 = 72