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.