Algebra Examples
(−3,−4) , (−2,−9)
Step 1
Step 1.1
Slope is equal to the change in y over the change in x, or rise over run.
m=change in ychange in x
Step 1.2
The change in x is equal to the difference in x-coordinates (also called run), and the change in y is equal to the difference in y-coordinates (also called rise).
m=y2−y1x2−x1
Step 1.3
Substitute in the values of x and y into the equation to find the slope.
m=−9−(−4)−2−(−3)
Step 1.4
Simplify.
Step 1.4.1
Simplify the numerator.
Step 1.4.1.1
Multiply −1 by −4.
m=−9+4−2−(−3)
Step 1.4.1.2
Add −9 and 4.
m=−5−2−(−3)
m=−5−2−(−3)
Step 1.4.2
Simplify the denominator.
Step 1.4.2.1
Multiply −1 by −3.
m=−5−2+3
Step 1.4.2.2
Add −2 and 3.
m=−51
m=−51
Step 1.4.3
Divide −5 by 1.
m=−5
m=−5
m=−5
Step 2
Step 2.1
Substitute the value of m into the slope-intercept form of the equation, y=mx+b.
y=(−5)⋅x+b
Step 2.2
Substitute the value of x into the slope-intercept form of the equation, y=mx+b.
y=(−5)⋅(−3)+b
Step 2.3
Substitute the value of y into the slope-intercept form of the equation, y=mx+b.
−4=(−5)⋅(−3)+b
Step 2.4
Rewrite the equation as (−5)⋅(−3)+b=−4.
(−5)⋅(−3)+b=−4
Step 2.5
Multiply −5 by −3.
15+b=−4
Step 2.6
Move all terms not containing b to the right side of the equation.
Step 2.6.1
Subtract 15 from both sides of the equation.
b=−4−15
Step 2.6.2
Subtract 15 from −4.
b=−19
b=−19
b=−19
Step 3
List the slope and y-intercept.
Slope: −5
y-intercept: (0,−19)
Step 4