how do we graph this equation 3x+4y=20
3x+4y=20 need to graph it with three points.
Solve the equation for y. It will then be in slope/intercept form.
3x + 4y = 20
4y = -3x + 20
y = -3/4 x + 5
That gives us one point, the y-intercept: (0, 5)
Now, choose two values for x, plug them into the equation,
and solve for y.
Use, x = 20.
y = -3/4 x + 5
y = -3/4(20) + 5
y = -15 + 5
y = -10
That gives us the point (20, -10)
Now use x = -20, to keep it simple.
y = -3/4 x + 5
y = -3/4(-20) + 5
y = 15 + 5
y = 20
That gives us the point (-20, 20)
Plot those three points on the graph and draw a line through them.