Home > Algebra > Write an Equation Given the Slope and a Point

How do you write an equation given points (-2,3), slope =4?

Answer 1

#y-3=4(x+2)#

So, you are going to need to memorize the format #y-y_1=m(x-x_1)#, just like how you need to memorize #y=mx+b#. Let me explain what #y_1# and #x_1# means. #y_1# is the #y# value in the first point, which is where the one is from, or you can say (although it's not the correct mathematical term) the second number in the parenthesis. m is slope as you know from #y=mx+b#. #x_1#, sort-of like our #y_1# is the x value of the first point, or the first number in the parenthesis.

Now that you know what each variable is, now you just need to plug in the numbers into the format: #y-y_1=m(x-x_1)#.

You might be wondering, why is the answer #y-3=4(x+2)#, I thought it was #x# minus #x_1#, not adding. Well you are correct, it just so happens to be that it is easier, and still correct to write #x# plus #x_1# because #x_1# is negative. Subtracting a negative is the same as adding so it is easier to write it that way.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Eva Abramson

The equation of the line given points (-2,3) and slope = 4 is y = 4x + 11.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.