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

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Answer 1 · 2018-02-28T17:18:26

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)#

Answer 2 · 2018-02-28T17:20:05

The numbers are #16 and 12.#

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#