The sum of a first and second number is 130. If the second number is 20 less than four times the first number, find the two numbers.

Question

nikato · Answer

So first set up 2 equations
Let a= first number and
b= second number
We know
a+b=130
b= 4a-20

Do you know how to solve from here?

anonymous · Answer

no

anonymous · Answer

@nikato

nikato · Answer

Have you learned substitution?

anonymous · Answer

yea but can you solve it 
@nikato

nikato · Answer

So using substitution,
a+4a-20=130
        +20.  +20
------------------
a+4a=150.     Combine like terms
5a=150.     Divide both sides by 5
So a=?

anonymous · Answer

a=30
@nikato

nikato · Answer

Sorry. This site crashed on me. I couldn't even message you. @cutegirl

And yes a=30
To find b, substitute this value of a into one of the original equation
Lets use a+b=130
So
30+b=130
So b=100