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Find equation of a line with the given slope that passes through the given point. Write the equation in the form Ax + By = C.

M = -5, (-4,-8)

User Jon Raynor
by
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1 Answer

13 votes
13 votes

Answer:

5x + y = -28

Explanation:

Hi there!

We're given that a line has a slope of -5 and contains the point (-4, -8)

We want to write the equation of this line in standard form

Standard form is given as ax+by=c, where a, b, and c are free integer coefficients, but a and b cannot be zero, and a cannot be negative

Before we write the equation in standard form however, we need to write it in slope-intercept form, which is y=mx+b, where m is the slope & b is the y intercept

As we are already given the slope, we can immediately plug that in for m in y=mx+b

y=-5x+b

Now to find b:

As the equation passes through the point (-4, -8), we can use its values to help solve for b

Substitute -4 as x and -8 as y:

-8 = -5(-4) + b

Multiply

-8 = 20 + b

Subtract 20 from both sides

-8 = 20 + b

-20 -20

__________

-28 = b

substitute -28 as b

y = -5x - 28

We found the equation in slope-intercept form, but remember, we want it in standard form

In standard form, both x and y are on the same side; so, let's move 5x to the other side; to do this, we need to add 5x to both sides

y = -5x - 28

+5x +5x

_________

5x + y = -28

Hope this helps!

User Reith
by
2.7k points