2022 Algebra 1 Part 1 Final Exam Review Part 1

Algebra 1 Part 1 2022 Final Exam Review

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Multiple Choice

What is the slope between the points (-3, 4) & (7, -6) ?

• 1

• - 1

• 1/2

• -1/2

x1 = -3 and y1 = 4

x2 = 7 and y2 = -6

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The line crosses the y-axis at 2 so the y-intercept is the point (0,2)

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y = 3x + 2

slope intercept form is y=mx+b

m = slope = 3

(found earlier with rise/run but you could also use the slope formula)

b = y-intercept = 2

Multiple Choice

Find the slope and y-intercept of y=-4/5x + 7

• slope is -4/5 and y-intercept is (0,7)

• slope is 7 and y-intercept is -4/5

When an equation is given in y=mx+b form you can find the slope and y-intercept by looking at the equation

m=slope

b=y-intercept

Multiple Choice

A positive slope is

• decreasing

• increasing

With a positive slope the line goes upward so it is increasing

Multiple Choice

A negative slope is

• decreasing

• increasing

With a negative slope the line goes down so the it is decreasing

Multiple Choice

Write 2x + 3y = 15 into slope-intercept form. (y=mx+b)

• y= 2/3x + 5

• y = - 2/3x + 5

• y = 2x + 15

• y = -2x + 15

Multiple Choice

What is the slope of 2x + 3y = 15?

Hint: You just solved this equation for y so it is in slope-intercept form

• -2/3

• - 2/3

• 2

• -2

Step 1: Solve for y so it is in y=mx+b form

Step 2: m is slope so the slope is -2/3

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Multiple Choice

What is the y-intercept of 3x + 5y = 15?

• (0,3)

• (0,5)

• (0,15)

• -3/5

Step 1: Solve for y so it is in y=mx+b form

Step 2: b is the y-int and b=3 so the y-intercept is (0,3)

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Multiple Choice

Write the equation of a line that has a slope of 3/5 and passes through (5,-2)

• y=3/5x - 2

• y = 3/5x - 5

• y = 3/5x + 5

Use the slope, x value of the point, and y value of the point in y=mx+b to find the b or your line.

y = 3/5x - 5

m = 3/5 (given) and b = -5 (found in the picture to the right)

Open Ended

The first step in writing an equation for a line of best fit is to find the slope of the line.

How do you find the slope of the line of best fit for this graph?

Your first step in writing an equation for a line of best fit is to find the slope using the slope formula

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Open Ended

The second step in writing an equation for a line of best fit is to find the y-intercept (b) of the line.

How do you find the y-intercept of the line of best fit for this graph?

Use y=mx + b to find the b of the line of best fit

you found the slope: m=2

from the point (5,7) x=5 and y=7

use those numbers for m, x and y in y=mx + b to find b

7 = 2(5) + b

7=10+b

-3 = b

Multiple Choice

Since you found that the slope of the line of best fit is 2 and the y-intercept of the line is -3 we can write the equation for the line of best fit:

y = 2x - 3

If x=20 then what is the y for the line of best fit

• 19

• 37

• 21.5

Substitute 20 into the x of y=2x-3

y=2(20) - 3

y = 40-3

y=37

Multiple Choice

Which equation is parallel to y=3/4x - 3?

• y = -3/4x + 1

• y = 4/3x + 1

• y = -4/3x + 1

• y=3/4x + 1

Parallel lines have the same slope

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Multiple Choice

Which equation is perpendicular to y = 3/4x + 5

• y = -4/3x + 6

• y = 4/3x + 6

• y = -3/4x + 6

• y = 3/4x + 6

To find the perpendicular slope you flip the fraction and change the sign

flip 3/4 to 4/3 and then make it negative so -4/3 is perpendicular to 3/4

Open Ended

Graph y = 3x +2.

m = 3 = 3/1

(up 3 right 1)

b = 2

(start on 2 on the y-axis)

b is the beginning point on the y-axis and m is how you move to the next point with rise/run