Two angles are supplementary. ∠QRS=x+40° and ∠SRT=x°. What is the value of ∠QRS?

70°

25°

110°

180°

110°

To find the value of ∠QRS, we need to recall that supplementary angles add up to 180 degrees. So, ∠QRS + ∠SRT = 180°.

Given that ∠QRS = x + 40° and ∠SRT = x°, we can substitute these values into the equation and solve for x:

(x + 40°) + x° = 180°

Combining like terms:

2x + 40° = 180°

Next, we isolate the term with x by subtracting 40° from both sides of the equation:

2x = 180° - 40°

Simplifying:

2x = 140°

Finally, we divide both sides of the equation by 2 to solve for x:

x = 140° / 2
x = 70°

Therefore, the value of ∠QRS is x + 40°, which means ∠QRS = 70° + 40° = 110°.

Hence, the correct answer is 110°.