Question

Suppose that x = 2+2t and y = t - 21. If x = 8, what is y?

Answer 1

`y=-18`

Explanation:

So we know that:

`x=2+2t\text{ and}\\y=t-21`

And we want to figure out the value of y when x is 8.

So first, substitute 8 into the first equation:

`8=2+2t`

Solve for t. Subtract 2 from both sides:

`6=2t`

Divide both sides by 2:

`t=3`

Now, substitute this into the second equation for t:

`y=(3)-21`

Subtract:

`y=-18`

So, the value of y is -18.

And we're done!