SOLUTION: Sketch the linear function f(x) = 1/2 (3x + 1) - 1. Which key feature of the graph is true? A) y-intercept (0, -1) B) x-intercept ( 1/6 , 0) C) x-intercept ( 1/3 , 0) D) y-in

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Sketch the linear function f(x) = 1/2 (3x + 1) - 1. Which key feature of the graph is true? A) y-intercept (0, -1) B) x-intercept ( 1/6 , 0) C) x-intercept ( 1/3 , 0) D) y-in      Log On


   



Question 1019919: Sketch the linear function f(x) = 1/2 (3x + 1) - 1. Which key feature of the graph is true?
A) y-intercept (0, -1)
B) x-intercept ( 1/6 , 0)
C) x-intercept ( 1/3 , 0)
D) y-intercept (0, 1/2 )
I am confused by this question on USATESTPREP could someone please help?

Found 2 solutions by LinnW, josgarithmetic:
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
Put the equation into the form y = mx + b
In this form , b represents the y intercept,
where the line crosses the x axis.
This crossing point is (0,b)
y = 1/2 (3x + 1) - 1
y = 3/2x + 1/2 - 1
y = 3/2x - 1/2
-1/2 is the b in the (0,b) or in this case (0,-1/2) y-intercept
A) and D) are incorrect because they have the wrong intercept.
The x-intercept is determined when the value of y is zero.
Substitute into y = 3/2x - 1/2 the value of zero for y
0 = 3/2x - 1/2
add 1/2 to each side
1/2 = 3/2x
Multiply each side by 2/3
2/6 = x
1/3 = x
So the answer is C) x-intercept ( 1/3 , 0 )

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Stated more clearly, f%28x%29=%281%2F2%29%283x%2B1%29-1 and is not quite in point-slope form, ....

The question is about identifying an axis intercept, so to finds x or y intercept, let the other variable be 0 and solve for the nonzero (if it is nonzero) variable.

Try start as y=%281%2F2%29%283x%2B1%29-1
2y=3x%2B1-2
2y=3x-1
and if put into slope-intercept form,
y=%283%2F2%29x-1%2F2 showing the y-intercept is (0, -1/2).

Let y=0 and solve for x, to find the x-intercept.