What is the sum of two number is 28 and their difference is 4 ???

Please help

2 Answers
Feb 28, 2018

Write an equation to satisfy the word problem:

overbrace"the sum of two number"^(x+y) overbrace"is"^(=) overbrace"28 and their difference"^(x-y) overbrace"is 4"^(=4)

This is a system of linear equations:

x+y=28
x-y=4

Add to get rid of y:

2x=32

x=16

Plug back in to solve for y

16+y=28

y=12

The answer is (16,12)

Feb 28, 2018

The numbers are 16 and 12.

Explanation:

you have to make and solve the system of equations:
x+y=28 and x-y=4

You start by adding the two equations together.

The positive and negative y terms will cancel leaving you with
2x=32

You then solve that equation to get:

x= 16

Next you substitute the 16 for x in either of the two original equations and solve that to get

y=12

Check:

12+16 = 28" " and" " 16-12 =4