Substitution method

4a=4-b

4a=5-b

How to do this

A "solution" to this pair of equations is a pair of numbers, for 'a' and 'b',

that make the equations true statements.

I can tell you right now that this system of equations has no solution.

Here, let me show you why:

4a = 4 - b

4a = 5 - b

Subtract the bottom equation from the top one:

0 = - 1

Can you think of any numbers for 'a' and 'b' that could

make 0 equal to - 1?

I can't either.

There are no numbers for 'a' and 'b' that can make both equations true

statements. That's just another way to say that the system of equations

has no solution.