1. A city map is laid out on a coordinate plane. Elm Street is described by the line x + 2y = -6. Oak street intersects Elm Street at an right angle. Which of the following could be the equation for Oak Street?

a. 2x + y = 5
b. -2x + y = 3
c. x + 2y = 4
d. -x - 2y = 8

My answer: d?

2. Which expression is NOT equivalent to 3/x-1?

a. (3x + 6)/(x^2 + x - 2)
b. (3x - 3)/(x^2 - 2x + 1)
c. (3x + 3)/(x^2 - 1)
d. (3x - 3)/(x - 1)

My answer: d?

1 answer

1. the slope of x+2y = -6 is -1/2
so we are looking for a line with slope +2
so anything starting with 2x-y = .... or -2x + y = ... will do.
looks like b) to me

2.
They all factor and simplify
a) 3(x+2)/((x+2)(x-1)) = 3/(x-1) , x ≠ -2
b) 3(x-1)/((x-1)(x-1)) = 3/(x-1) , x ≠ 1
c) 3(x+1)/((x+1)(x-1) = 3/(x-1) , x≠ -1
so far they are all equal
so if there is an answer it must be d)
d) 3(x-1)(x-1) = 3 , which is not the same as 3/(x-1)

you were right with d)