y-7=4(x+4)y−7=4(x+4)
This is in the format of y-y_1= m(x-x_1)y−y1=m(x−x1) which is known as the point-slope form. To change this to standard form (Ax+By=CAx+By=C), you need to find the values of the points (x_1,y_1)(x1,y1) and the slope (mm):
y-7=4(x+4)y−7=4(x+4)
y-y_1= m(x-x_1)y−y1=m(x−x1)
Therefore,
(x_1,y_1) = (-4, 7)(x1,y1)=(−4,7) and m=4m=4
y-7=4(x+4)y−7=4(x+4)
Now simplify and rearrange to get xx and yy terms on one side and constants on the other side of equal sign:
y-7=4(x+4)y−7=4(x+4)
y-7=4x+16y−7=4x+16
y=4x+16+7y=4x+16+7
y=4x+23y=4x+23
-4x+y=23−4x+y=23
This is almost in the format of Ax+By=CAx+By=C but AxAx cannot have a negative sign in front of it. To get rid of this negative, divide both sides of the equation by -1−1:
(-4x+y)/-1=23/-1−4x+y−1=23−1
4x-y=-234x−y=−23
Now the equation is in standard form because A=4A=4, B=-1B=−1 and C=-23C=−23.