I'm confused on two questions that are kind of similiar:

Question

State the slope and y-intercept of
y= -1/2x
I know the slope is -1/2 but I don't know the y-intercept

State the slope and y-intercept of
y= 3x-4
I know the slope is 3, but I don't know if the y-intercept is 4 or -4.

Answer 1

y-intercept is a point where the graph of a function intersects with the y-axis

y-intercept is value of y where x=0

y= -1/2x

Slope -1/2

y-intercept y= -1/2*0= -1/0= +/- infinity

y= 3x-4

Slope 3

y-intercept y=3*0-4=0-4= -4

Answer 2

If yor function:
y= -1/2x

mean y=(-1/2)*x

then:

Slope -1/2

y-intercept y=(-1/2)*0= 0