3x+y=15

Subtract 3x from both sides of the equation.

y=15-3x

The slope-intercept form is y=mx+b, where m is the slope and b is the y-intercept.

y=mx+b

Reorder 15 and -3x.

y=-3x+15

y=-3x+15

Find the values of m and b using the form y=mx+b.

m=-3

b=15

The slope of the line is the value of m, and the y-intercept is the value of b.

Slope: -3

y-intercept: 15

Slope: -3

y-intercept: 15

Choose 3 to substitute in for x to find the ordered pair.

Replace the variable x with 3 in the expression.

f(3)=-3⋅3+15

Simplify the result.

Multiply -3 by 3.

f(3)=-9+15

Add -9 and 15.

f(3)=6

The final answer is 6.

6

6

The y value at x=3 is 6.

y=6

y=6

Choose 2 to substitute in for x to find the ordered pair.

Replace the variable x with 2 in the expression.

f(2)=-3⋅2+15

Simplify the result.

Multiply -3 by 2.

f(2)=-6+15

Add -6 and 15.

f(2)=9

The final answer is 9.

9

9

The y value at x=2 is 9.

y=9

y=9

Create a table of the x and y values.

xy2936

xy2936

Graph the line using the slope and the y-intercept, or the points.

Slope: -3

y-intercept: 15

xy2936

Graph 3x+y=15