What is the value of x?

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:
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:
[tex] 2 5 x + ( 5 7 + x ) + ( 1 8 0 - 4 5 x ) = 180 [/tex]
[tex]25x+x-45x=180-180-57[/tex]
[tex]-19x=-57[/tex]
[tex]x=\frac{-57}{-19}[/tex]
x = 3