Question

Can anyone tell me what the answer please

Answer 1

What you're looking at in this image are two alternate exterior angles.

Alternate exterior angles, are, essentially, exterior angles of a transversal that runs through two parallel lines. These angles are on alternating sides. These angles, assuming the lines are parallel, must be equal.

There's a proof behind why these angles are equal, but I won't bore you with the specifics as the question doesn't require it.

So - we know that these two angles must be equal to prove that the lines A and B are parallel. Knowing this, we can write an equation:

5x + 20 = 3x + 60

Subtract 20 from both sides:

5x + 20 - 20 = 3x + 60 - 20

5x = 3x + 40

Subtract 3x from both sides:

5x - 3x = 3x - 3x + 40

2x = 40

x = 20

If you have any questions on how I got to the answer, just ask!

- breezyツ