You need to use the equation that relates the slopes of parallel lines, such that:
`m_1 = m_2`
`m_1` represents the slope of P
`m_2` represents the slope of Q
The problem provides the slopes of P and Q, such that:
`5 = 10/v`
You need to perform cross multiplication, such that:
`10*1 = 5*v => v = 10/5 => v = 2`
Hence, evaluating v, under the given conditions, yields that v is 2.
If 2 lines are parallel, the values of their slopes are equal.
If the slope of P is mP = 5, then the slope of Q is mQ = 5 also.
We know, from enunciation, that the slope of Q is the ratio 10/v.
We'll put equal the following:
mQ = 5 (1)
mQ = 10/v (2)
(1) = (2)
5 = 10/v
We'll divide by 5 both sides:
5/5 = 10/5v
1 = 2/v
We'll multiply by v both sides:
v = 2
So, the value of v = 2 for the parallel lines P and Q, whose slopes are m = 5.