Question #44498

1 Answer
Sep 21, 2017

#color(green)(x=12 and y=8)#

Explanation:

Let the two numbers be x and y.

So from what you said we know that #x+y = 20#.

We also know that #x-y = 4#.

Now if we rearrange the equation to make x the subject we get.

#x=y+4#

Now that we know the value of x let's substitute this into the equation #x+y=20#.

#(y+4)+y = 20# this can be rewritten as #2y+4 = 20#

Let's solve it!

Subtract both sides by 4

#2y+4 color(red)((-4))=20color(red)((-4)#

this gives us

#2y=color(green)(16)#

Divide both sides by 2

#2y color(red)(÷2)= 16color(red)(÷2)#

this gives us

# color(green)(y = 8)#

Now let us find the value of x via substitution.

#x+8=20#

Subtract both sides by 8
#x+8color(red)((-8))=20color(red)((-8)#

so we get x as

#color(green)(x=12)#