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27 votes
27 votes
Find the intercepts of the function y = 3x + 9

User Karema
by
3.1k points

2 Answers

18 votes
18 votes

Explanation:

To solve for the x-intercept, set y=0 then solve for x.

y=−3x−9. 0=−3x−9. 3x=−9.

x=−3 when y=0.

To solve for the y-intercept, set x=0 then solve for y.

y=−3x−9. y=−3(0)−9. y=−9 when x=0.

User Zingam
by
3.6k points
12 votes
12 votes

Hi there!

Y-intercept:

Set the x value to 0:

y = 3(0) + 9

y = 9 --> (0, 9)

X-intercept:

Set the y value to 0:

0 = 3x + 9

Solve for x:

-9 = 3x

x = -3 --> (-3, 0)

User Phxhawke
by
2.8k points