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Find the x- and y-intercepts of the equation 3x - 7y= 21.

Find the x- and y-intercepts of the equation 3x - 7y= 21.-example-1
User Loomer
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1 Answer

2 votes

Answer: (

We are given the equation, 3x - 7y = 21

This is a slope - intercept equation

y = mx + b

Firstly, we need to re arrange the equation

-7y = 21 - 3x

7y = 3x - 21

To find x and y intercepts, we need to isolate the variables individually

To find the value of y let x = 0

Substsitute the value of x = 0 into the equation

7y = 3(0) - 21

7y = 0 - 21

7y = -21

Divide both sides by 7

7y/7 = -21/7

y = -21/7

y = -3

(0, -3)

To find x, let y = 0

7y = 3x - 21

7(0) = 3x - 21

0 = 3x - 21

Make 3x the subject of the formula

0 - 3x = -21

-3x = -21

Divide both sides by -3

-3x/-3 = -21/-3

x = 21/3

x = 7

(7, 0)

The x- intercept is (7, 0) and y- intercept is (0, -3)

The answer is OPTION C

User Michael Klemm
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