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35 votes
35 votes
Use an equation to find the value of k

so that the line passing through (−4,k)
and (6,−7)
has a slope of −15

User Chris Eldredge
by
2.8k points

1 Answer

23 votes
23 votes

Answer: k=143

Explanation:

Let's start with the standard form of a linear equation: y = mx + b, where m ios the slope and b is trhe y-intercept (the value of y when x=0). We know the slope, so:

y = -15x + b

We can find the y-intercept, b, by using the one given point (6,-7) in the equation and solve for b:

y = -15x + b

-7 = -15(6) + b

-7 = -90+b

b = 83

The equation is y = -15x + 83

Use the x value of (-4,k) to find y, which will be k.

y = -15x + 83

y = -15(-4) + 83

y = 60 + 93

y = 143

k is 143

User Nickey
by
2.6k points