Question

Write an equation in slope-intercept form of the line that passes through the points (1, 2) and (-2, -1)
y=

Answer 1

Answer:

y=x+1

Step-by-step explanation:

Firstly, we need to know that the slope intercept form is known as:

y=mx+b, where y and x are coordinates, m is the slope and b is the y intercept.

We need to find m first, and then b. By doing that, we use the formula:

$\frac{y1-y2}{x1-x2} \\\\\\y1=2\\y2=-1\\x1=1\\x2=-2$

Plugging those values in, we get:

$m= \frac{2-(-1)}{1-(-2)} \\\\= \frac{3}{3} \\=1$

So with this information, we already know that y=1x+b. We just need to find b.

So we can pick one of the two coordinates given. Let's use (1,2) and plug those in.

2=1(1)+b

Now with that, we solve for b.

2=1+b

2-1=b

1=b

b=1

Therefore, we have the final equation of y=1x+1

or better,

y=x+1

Answer 2

The equation is y=x+1