Solve the system by graphing

Question

5x + 5/2y= -10 3/2x - 3/4y= -6

Answer 1

The equations are 5x+5/2y = -10  and 3/2x - 3/4y = - 6

First line 5x+5/2y = -10

5/2y = -5x - 10

Multiply each side by 2/5.

y = -2x - 4

Write the equation with slope-intercept form y = mx + b.

y = -2x - 4

slope = -2 and y -intercept is -4.

y -intercept is -4, so the line crosses the y -axis at (0, -4)

Using slope find the next point.

Slope = rise/run = 2/-1

Start at point (0,-4), move 2 unit down and 1 unit left, then plot the point (-1, -2).

Draw a line through these points.

Now  the second line 3/2x - 3/4y = - 6

- 3/4y = -3/2x - 6

Multiply each side by -4/3.

Write the equation with slope-intercept form y = mx + b.

y = 2x+8

slope = 2 and y -intercept is 8.

y -intercept is 8, so the line crosses the y -axis at (0, 8)

Using slope find the next point.

Slope = rise/run =  -2/-1

Start at point (0, 8), move 2 unit down and 1 units left, then plot the point (-1, 6).

Draw a line through these points.

Observe the graph two lines are intersecting at (-3,2)

Solution from the graph is x= -3 y = 2.