Question

write an equation of the line containing the given point and parallel to the given line (9,-9); 3x-5y=8

Answer 1

The most useful form of straight-line equations is the "slope-intercept" form:

y = mx + b

m is the slope and "b" gives the
y-intercept.

3x-5y=8

-5y=8-3x Divide with -5

y=(-8/5)+(3x/5)

y=(3/5)x-8/5

The other format for straight-line equations is called the "point-slope" form. For this one, they give you a point (x1, y1) and a slope m, and have you plug it into this formula:

y-y1= m(x – x1)

Parallel lines have same slope.

In this case:

m=3/5

x1=9

y1= -9

y-y1= m(x – x1)

y-(-9)=(3/5)*(x-9)

y+9=(3/5)x-(3*9/5)

y=(3/5)x-(27/5)-9

y=(3/5)x-(27/5)-(45/5)

y=(3/5)x-72/5

OR:

y-(3/5)x= -72/5 Multiply with -5

-5y+3x=72

3x-5y=72













y=(1/4)x-6