Tayler claims that when a linear equation is written in general form, Ax + By + C = 0, the

x-intercept of the corresponding graph is always - (C/A)

a) Show that Tayler's claim is true for the equation 3x+5y + 45 = 0

b. Explain why - (C/A) represents the x-intercept. (Hint: What y-value can be substituted into Ax + By + C = 0 to determine the x-intercept?)

c. Tayler's claim is not true for horizontal lines. Explain why.

d. Suggest a similar rule for the y-intercept. Check the rule using 3x+5y + 45 = 0.

Question

Mathematics

Katrina Dickson

21 April, 12:29

Tayler claims that when a linear equation is written in general form, Ax + By + C = 0, the

x-intercept of the corresponding graph is always - (C/A)

a) Show that Tayler's claim is true for the equation 3x+5y + 45 = 0

b. Explain why - (C/A) represents the x-intercept. (Hint: What y-value can be substituted into Ax + By + C = 0 to determine the x-intercept?)

c. Tayler's claim is not true for horizontal lines. Explain why.

d. Suggest a similar rule for the y-intercept. Check the rule using 3x+5y + 45 = 0.

+3

Answers (1)

Know the Answer?

Lilianna Sims · Answer 1

Ax + By + C = 0

A. 3x + 5y + 45 = 0

3x + 5 (0) + 45 = 0

3x = - 45

x = - 45/3 ... x int ... - C/A

x = - 15

B. To find the x intercept, u must sub in 0 for y and solve for x

C. This is not true for a horizontal line because u can't sub in 0 for x because a horizontal line never crosses the x axis and therefore, does not have an x axis.

D. y int is - C/B ... u find this by subbing in 0 for x and solving for y

3x + 5y + 45 = 0

3 (0) + 5y + 45 = 0

5y = - 45

y = - 45/5 ... y int = - C/B

y = - 9