Answer:
y = -3x - 4
Step-by-step explanation:
We are given the equation 3x + y = 3, and we want to find an equation of the line that is parallel to 3x + y = 3.
This same line also passes through the point (1, -7).
Parallel lines have the same slopes. This means that we'll first need to find the slope of 3x + y = 3.
The equation is written in standard form, which is ax+by=c, where a, b, and c are free integer coefficients, but a and b cannot be 0. a is usually non-negative as well.
There is a shortcut into finding the slope when the equation is in standard form; the slope of the line is -a/b, where a is the coefficient in front of x and b is the coefficient in front of y).
The coefficient in front of x is 3, and 1 in front of y.
Substitute 3 as a, and 1 as b in -a/b. Don't forget about the - in front of a!
-3/1 = -3
This means the slope of the line is -3.
It is also the slope of the line parallel to it.
We can write the equation of the line we are trying to solve for in standard form, too. However, we could also write it in slope-intercept form.
Slope-intercept form is given as y=mx+b, where m is the slope and b is the y intercept.
As we are already given the slope, we can immediately plug that into the formula.
Replace m with -3.
y = -3x + b
Now we need to find b.
As the equation passes through the point (1, -7), we can use its values to help solve for b.
Substitute 1 as x and -7 as y.
-7 = -3(1) + b
Multiply.
-7 = -3 + b
Add -3 to both sides
-4 = b
Substitute -4 as b into the equation
y = -3x - 4