For full tracking and unlimited access to thousands of activities

Given the formula y = 2x + 3, we can test to see whether the solution  (4,10) works.

Remember that in (4,10), the first number is the x number so this means that 

x = 4 and  y = 10

We substitute x = 4 into the formula to see whether it gives y = 10.

 

y = 2x + 3

y = 2 times x + 3

y = 2 x 4 + 3

y = 8 + 3

y = 11

 

So x = 4, y = 10 does not fit.

10 questions