Question x-y-18

1.3 Linear Equations in Two Variables - Intercepts and slope applications
0:00
x y
18 130
23 160
26 178

For line h , the table shows three values of x and their corresponding values of y . Line k is the result of translating line h down 5 units in the xy-plane. What is the x-intercept of line k ?

A.

-263,0

B.

-92,0

C.

-113,0

D.

-176,0

x y 18 130 23 160 26 178 For line h , the table shows three

Hard-difficulty · SAT Math · Linear Equations in Two Variables — Intercepts and slope applications. Read the question above, select your answer, and check the full explanation below to understand exactly why the correct choice works.

Answer explanation

Choice D is correct. The equation of line h can be written in slope-intercept form y = m x + b , where m is the slope of the line and 0,b is the y-intercept of the line. It’s given that line h contains the points 18,130, 23,160, and 26,178. Therefore, its slope m can be found as 160-13023-18, or 6 . Substituting 6 for m in the equation y = m x + b yields y = 6 x + b . Substituting 130 for y and 18 for x in this equation yields 130=6(18)+b, or 130=108+b. Subtracting 108 from both sides of this equation yields 22 = b . Substituting 22 for b in y = 6 x + b yields y = 6 x + 22 . Since line k is the result of translating line h down 5 units, an equation of line k is y=6x+22-5, or y = 6 x + 17 . Substituting 0 for y in this equation yields 0 = 6 x + 17 . Solving this equation for x yields x=-176. Therefore, the x-intercept of line k is -176,0.

Choice A is incorrect and may result from conceptual or calculation errors.

Choice B is incorrect and may result from conceptual or calculation errors.

Choice C is incorrect and may result from conceptual or calculation errors.