Can someone please help me I really need help please help me thank you

This is modelling the exterior angle formula which states that the measure of an exterior angle is equal to the sum of the measures of its two remote interior angles. Therefore, the answer is x = a + b.

x = a+b

Step-by-step explanation:

The exterior angle of a triangle is equal to the sum of the opposite interior angles

x = a+b

11.2

step-by-step explanation:

when doing tangent the tangent of the angle is equal to the opposite side from the angle over the adjacent side to the angle.

tan43 = x / 12

move 12 over by multiplying each side by 12

12tan43 = x

x = about 11.2