How do you graph the line 2x - 5y=10?

1 Answer
Apr 10, 2016

Transpose (manipulate) the equation as follows:

Add color(blue)(5y) to both sides

color(brown)(2x-5ycolor(blue)(+5y)=10color(blue)(+5y))" "->" "2x+0=10+5y

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtract color(blue)(10) from both sides

color(brown)(2xcolor(blue)(-10)=10color(blue)(-10)+5y)" "->" "2x-10=0+5y

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Divide both sides by color(blue)(5)

color(brown)( (2x)/(color(blue)(5)) -10/(color(blue)(5)) = 5/(color(blue)(5)) xx x

But 5/5=1

color(blue)(y=2/5 x-2)" " This is standard form of the equation
color(red)("=================================")

The line crosses the y-axis ( y_("intercept" ) when x=0

so y_("intercept")= 2/5 (0)-2 = -2

So one point is:" "(x,y)->(0,-2)

color(red)("Mark that point on the graph")
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The line crosses the x-axis ( x_("intercept") ) at y=0

0=2/5 x-2

=> 2 xx5/2=x = 5

So the other point is:" "(x,y)->(5,0)
color(red)("Mark that point on the graph")
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(blue)("Draw a line through both these points and that is your graph.")

Tony B