Question

The line passing through (0, 2) and (−3, −1) is parallel to the line passing through (−1, 5) and (4, a). Find a.

Answer 1

Slope of the line passing through (0, 2) and (−3, −1)

= `(-1 - 2)/(-3 - 0)`

= `(-3)/(-3)`

= 1

Slope of the line passing through (−1, 5) and (4, a)

= `(a - 5)/(4 + 1)`

= `(a - 5)/5`

Since, the lines are parallel.

∴ `1 = (a - 5)/5`

a – 5 = 5

a = 10