Answer:
Option C. x=7
Step-by-step explanation:
we know that
If PQ is parallel to BC
then
triangles APQ and ABC are similar
Remember that
If two figures are similar them the ratio of its corresponding sides is proportional
so
[tex]\frac{AP}{AB}=\frac{AQ}{AC}[/tex]
substitute the values
[tex]\frac{x}{x+7+x}=\frac{x-3}{x-3+x+1}[/tex]
Solve for x
[tex]\frac{x}{2x+7}=\frac{x-3}{2x-2}\\ \\x(2x-2)=(2x+7)(x-3)\\ \\2x^{2}-2x=2x^{2}-6x+7x-21\\ \\3x=21\\ \\x=7\ units[/tex]
