Question

Line A and Line B are parallel. The slope of Line A is -2. What is the value of x if the slope of Line B is 3x + 3?

Answer 1

`x=-5/3`

Explanation:

Let `m_A` and `m_B` be the gradients of lines A and B respectively, if A and B are parallel, then `m_A=m_B`

So, we know that `-2=3x+3`

We need to rearrange to find `x`

`-2-3=3x+3-3`

`-5=3x+0`

`(3x)/3=x=-5/3`

Proof:
`3(-5/3)+3=-5+3=-2=m_A`