Question

Find the equation of the straight line that passes through points (-1; -2) and (3; 4)

Answer 1

Y=mx+b is our base equation

m=slope, so let's find that first:
m= change in y/change in x
So between the points (-1,-2) and (3,4),
The y values, -2 and 4, have a difference of 6. The x values, -1 and 3, have a difference of 4. This makes our slope 6/4 (or 3/2 simplified)

Now our equation is
Y=3/2x + b

We still need to find b
To find b, we can substitute a point given to us. Let's use (3,4) just to avoid negatives.

4=3/2(3) + b
Multiply
4=9/2 + b
Subtract 9/2 from both sides
-1/2=b

Now let's put it all back together!

Y=3/2x-1/2 Is the answer.

I hope this Helps!