Question

Here is some information 20= a+b, b is two more than a, what are the values of a and b?

Please can someone explain to me how I would go about solving this?

Answer 1

a= 9, b= 11

Explanation:

20= a +b

Let's rewrite this so that the variables are on the left-hand side of the equation:

a +b= 20 -----(1)

I have also labelled the equation as equation (1).

Since b is two more than a,

b= a +2 -----(2)

Label the equation as equation (2).

Substitute (2) into (1):

a +(a +2)= 20

2a +2= 20

-2 on both sides of the equation:

2a= 20 -2

2a= 18

Divide both sides by 2:

a= 18 ÷2

a= 9

Substitute a= 9 into (2):

b= a +2

b= 9 +2

b= 11