Question

1) suppose y varies directly with x, and y=12 when x=-3, what is the value of y when x=6?


A) -24****

B) 2

C) -2

D) -4


2) what is the equation of a line with a slop of -7 and a y-intercept of 6?


A) 6y = -7x

B) y = 6x + (-7)

C) -7y = x + 6****

D) y = -7x + 6


3) what is the equation of the line through (5,1) with a slope of -3


A) y + 1 = 3(x + 5)

B) y - 1 = 3(x - 5)****

C) y - 1 = -3(x - 5)

D) y + 1 = -3(x - 5)

4) what is the equation of the given line in point-slope form?

A) y - 1 = 2(x + 2)

B) y - 1 = 2(x - 2)

C) y - 2= 2(x - 1) ****

D) y - 2 = 1/2(x +2)

If anyone could please go over my answers and give me sources to get a better understanding of this then it would be greatly appreciated, thank you in advance .

Answer 1

#1 ok
#2 nope.
y = mx+b
has slope m and y-intercept b
so, not C
#3 almost. You picked the one with slope=3, not -3
#4 all the equations are in point-slope form, but I have no idea what the line looks like.