Question

Find the output,y,when the input,x is 5
Y=5x-3

Answer 1

At first, I changed the x for 5 so we can multiply it by 5 so :
Y=5x-3
Y=5(5)-3
Y= 15-3
Y= 12
With this, we know that 12 is the input of Y, and to be sure I replaced the Y by 12 so that the result can be the 5 given for X to confirm it.
Y=5x-3
12=5x-3
15=5x
5=x

So it's correct.
X=5 and Y=12