# Graph 7x-8y=15

7x-8y=15
Solve for y.
Subtract 7x from both sides of the equation.
-8y=15-7x
Divide each term by -8 and simplify.
Divide each term in -8y=15-7x by -8.
-8y-8=15-8+-7x-8
Cancel the common factor of -8.
Cancel the common factor.
-8y-8=15-8+-7x-8
Divide y by 1.
y=15-8+-7x-8
y=15-8+-7x-8
Simplify each term.
Move the negative in front of the fraction.
y=-158+-7x-8
Dividing two negative values results in a positive value.
y=-158+7×8
y=-158+7×8
y=-158+7×8
y=-158+7×8
Rewrite in slope-intercept form.
The slope-intercept form is y=mx+b, where m is the slope and b is the y-intercept.
y=mx+b
Reorder -158 and 7×8.
y=7×8-158
Rewrite in slope-intercept form.
y=78x-158
y=78x-158
Use the slope-intercept form to find the slope and y-intercept.
Find the values of m and b using the form y=mx+b.
m=78
b=-158
The slope of the line is the value of m, and the y-intercept is the value of b.
Slope: 78
y-intercept: -158
Slope: 78
y-intercept: -158
Any line can be graphed using two points. Select two x values, and plug them into the equation to find the corresponding y values.
Choose 1 to substitute in for x to find the ordered pair.
Replace the variable x with 1 in the expression.
f(1)=7(1)8-158
Simplify the result.
Multiply 7 by 1.
f(1)=78-158
Combine the numerators over the common denominator.
f(1)=7-158
Subtract 15 from 7.
f(1)=-88
Divide -8 by 8.
f(1)=-1
-1
-1
The y value at x=1 is -1.
y=-1
y=-1
Choose 0 to substitute in for x to find the ordered pair.
Replace the variable x with 0 in the expression.
f(0)=7(0)8-158
Simplify the result.
Multiply 7 by 0.
f(0)=08-158
Combine the numerators over the common denominator.
f(0)=0-158
Subtract 15 from 0.
f(0)=-158
Move the negative in front of the fraction.
f(0)=-158
-158
-158
The y value at x=0 is -158.
y=-158
y=-158
Create a table of the x and y values.
xy0-1581-1
xy0-1581-1
Graph the line using the slope and the y-intercept, or the points.
Slope: 78
y-intercept: -158
xy0-1581-1
Graph 7x-8y=15

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