Big Ideas Math: Modeling Real Life, Grade 8
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Big Ideas Math: Modeling Real Life, Grade 8 View details
2. Slope of a Line
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Exercise 35 Page 154

Substitute the given information into the Slope Formula and solve for the variable.

k=8

Practice makes perfect

The Slope Formula is used to determine the slope m of the line that connects two given points, ( x_1, y_1) and ( x_2, y_2). m=y_2- y_1/x_2- x_1Here, we are given the slope of a line and two points, one of them with a missing coordinate. When we substitute these values into the Slope Formula, it does not matter which point we choose to use as ( x_1, y_1) or ( x_2, y_2). Both will give the same result. 3/4=-1-( -4)/k- 4 or 3/4=-4-( -1)/4- k We will use the points in the given order and solve for the unknown coordinate.

m = y_2-y_1/x_2-x_1
3/4=-1-( -4)/k- 4
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Solve for k
3/4=-1+4/k-4
3/4=3/k-4
(k-4)(3/4)=3
3/4 * k-3/4 * 4=3
3k/4-3/4 * 4=3
3k/4-3=3
3k/4=6
3k=24
k=24/3
k=8