Question

What is the value of x?

Answer 1

Answer:

x = 3

Step-by-step explanation:

The external angle of a triangle is equal to the sum of the 2 opposite interior angles.

∠TRQ is an external angle and ∠RTS, ∠RST are interior angles, hence

45x = 25x + 57 + x

45x = 26x + 57 ( subtract 26x from both sides )

19x = 57 ( divide both sides by 19 )

x = 3

Answer 2

Answer:

x = 3

Step-by-step explanation:

We are given expression for measure of angles of two corners of a triangle, while for the third corner, we know the exterior angle.

We know that the sum of all three angles of a triangle is 180°.

So we can write it as:

$2 5 x + ( 5 7 + x ) + ( 1 8 0 - 4 5 x ) = 180$

$25x+x-45x=180-180-57$

$-19x=-57$

$x=\frac{-57}{-19}$

x = 3