Answer:
28
Step-by-step explanation:
A triangle always has 180° so that means 40° (2x+9)° and another angle add up to 180°.
We can find out two angles in order to find out the third, one of them is 40° the other is 180°-105° because there are 180° on a line.
you get 75.
75°+40°=115°
180°-115°=65°
2x+9=65°
Make x the subject of the formula:
2x=56
(take away 9)
x=28
(divide both sides by 2)
