Pearson Algebra 1 Common Core, 2011
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Pearson Algebra 1 Common Core, 2011 View details
Mid-Chapter Quiz
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Exercise 22 Page 321

Start by using the Slope Formula to find the slope.

y=5x

Practice makes perfect
An equation in slope-intercept form follows a specific format. y= mx+b For an equation in this form, m is the slope and b is the y-intercept. Let's use the given points to calculate m. We will start by substituting the points into the Slope Formula.
m=y_2-y_1/x_2-x_1
m=10-( -5)/2-( -1)
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Simplify right-hand side
m=10+5/2+1
m=15/3
m=5
A slope of 5 means that for every 1 horizontal step in the positive direction, we take 5 vertical steps also in the positive direction. Now that we know the slope, we can write a partial version of the equation. y= 5x+b To complete the equation, we also need to determine the y-intercept, b. Since we know that the given points will satisfy the equation, we can substitute one of them into the equation and solve for b. Let's use ( 2, 10).
y=5x+b
10=5( 2)+b
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Solve for b
10=10+b
0=b
b=0
A y-intercept of means that the line crosses the y-axis at the point (0, ). We can now complete the equation. y= 5x+ ⇔ y=5x