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How would I graph 5x+3y=-15? How would I graph 8x+2y=-4? Is the x=8/-3 the x-intercept for the equation -3x+4y=8? 

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One method to graph is to find the x and y intercept of the equation. Then use the intercepts to graph the line.

 

Example 1:  `5x+3y=-15`

To find the x-intercept of the linear equation let y=0 and solve for the x value.

`5x+3y=-15`

`5x+3(0)=-15`

`5x=-15`

x=-3

Therefore one point on the line is the coordinate (-3, 0).

To find the y=intercept of the linear equation let x=0 and solve for the y value.

`5x+3y=-15`

`5(0)+3y=-15`

`3y=-15`

`y=-5`

Therefore a second point on the line is the coordinate (0, -5).

Plot the points (-3, 0) and (0, -5) and draw a line through the two points.

 

 

The same method can be used for the second example.

Example 2: `8x+2y=-4`

To find the x-intercept of the linear equation let y=0 and solve for the x value.

`8x+2y=-4`

`8x+2(0)=-4`

`8x=-4`

`x=-1/2`

Therefore one point on the line is the coordinate (-1/2, 0).

To find the y=intercept of the linear equation let x=0 and solve for the y value.

`8x+2y=-4`

`8(0)+2y=-4`

`2y=-4`

`y=-2`

Therefore a second point on the line is the coordinate (0, -2). Plot the points (-1/2, 0) and (0, -2) and draw a line through the two points.

 

Example 3: `-3x+4y=8`

To find the x-intercept of the linear equation let y=0 and solve for the x value.

`-3x+4y=8 `

`-3x+4(0)=8`

`-3x=8`

`x=-8/3`

Therefore one point on the line is the coordinate (-8/3, 0). To find the y=intercept of the linear equation let x=0 and solve for the y value.

`-3x+4y=8`

`-3(0)+4y=8`

`4y=8`

`y=2`

Therefore a second point on the line is the coordinate (0, 2). Plot the points (-8/3, 0) and (0, 2) and draw a line through the two points.

 

 

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