Question

What is the value of y so that the line passing through (3, y) and (2, 7) is parallel to the line passing through (-1, 4) and (0, 6)?

• A. 9
• B. -9
• C. $\frac{1}{9}$
• D. $-\frac{1}{9}$

Answer 1

The correct option is A 9

When two lines are parallel their slopes are equal.

$\frac{7-y}{2-3}=\frac{6-4}{0-(-1)}$

$\Rightarrow \frac{7-y}{-1}=\frac{2}{1}\Rightarrow 7-y=-2$

$\Rightarrow -y=-2-7\Rightarrow -y=-9$

$\therefore y=9$

So, option a is correct.