Question

What is the value of x for which m || n? x = 40 x = 5 x = 105 x = 30

Answer 1

m || n

3x - 15 = 105
3x = 120
  x = 40

answer
x = 40

Answer 2

Answer:

(A) x=40

Step-by-step explanation:

Given: It is given that m is parallel to n.

To find: The value of x.

Proof: It is given that m is parallel to n, from the figure it can be seen that 105° and (3x-15)° forms alternate exterior angles which are equal in measure because m is parallel to n.

Thus, $105^{\circ}=3x-15^{\circ}$

⇒$105^{\circ}+15^{\circ}=3x$

⇒$120^{\circ}=3x$

⇒$\frac{120}{3}=x$

⇒$x=40$

Thus, the value of x is 40, hence option A is correct.