Write the equation that passes through the point (-2.-9) and has a slope of 7

Hi Marlin;

Let's use the point-slope formula...

y-y

_{1}=m(x-x_{1})m is the slope.

y--9=7(x--2)

Subtracting a negative number is the same as adding a positive number...

y+9=7(x+2)

y+9=7x+14

Let's subtract 9 from both sides...

-9+y+9=7x+14-9

y=7x+5

The formula is now in the format of...

y=mx+b

This is known as slope-intercept.

m is the slope.

b is the y-intercept, the value of y when x=0.

Standard formula is...

Ax+By=C

Neither A nor B equal zero.

A is greater than zero.

y=7x+5

Let's move 7x to the left side of the equation. It becomes negative.

-7x+y=5

Let's multiply both sides by -1 to render A greater than zero.

-1(-7x+y)=(5)(-1)

7x-y=-5

This is the equation in standard form.