Im confused as to why ive got it wrong

, or just , when you're entering it in

Step-by-step explanation:

So, the gradient-intercept form of a line in the xy-plan is

Where m is the gradient of the line and b is its y-intercept. We already know the gradient for part c) is 3. With just this piece, we can write the equation

but how can we find b?

This is where that point (4, 2) comes in. This point gives us a known pair of x and y for our equation, and with those filled in, b becomes an unknown we can solve for. Let's plug those values in:

Replacing the 4 and 2 with x and y and the b with -10, our general equation is now