∠tuv and ∠mno are supplementary. m∠tuv = 75° and m∠mno = (5x)°. find the value of x and the measure of ∠mno

The measure of angle MNO is 105, and the value of x is 21.
This can be figured out through the equation 75 + 5x = 180
first, you add -75 to both sides to cancel it out from the left, and are left with 5x = 105
there, we know that MNO is 105 because 105 = 5x = MNO
to figure out the value of x, then, you divide both sides by 5 to get 21.

Supplementary=180. so the given is 75°, subtract that from 180. then set up an equation 5x=105. divide 105 by 5 and the answer you get is the degree of the angle.