What’s a larger number is two less than four times a smaller. if the sum of the number is 18

Let x be the larger number and y be the smaller number.
Using the given info, we get
x = 4y - 2
We also know that 
x + y = 18
Substitute x = 4y -2 into x + y = 18
(4y -2) +y = 18
5y - 2 = 18
5y = 20
y = 4
Enter this value into x = 4y - 2
x = 4(4) - 2
x = 14
The larger number is 14 and the smaller one is 4.

The linear equation is: y=ax+b