Ois the center of the given circle. the measure of angle o is 128°. the diagram is not drawn to scale. assuming that lines that appear to be tangent are tangent, what is the value of x?

We know that

The measure of the external angle is the semi difference of the arcs that it covers.
so
see the picture attached to better understand the problem

m AB=128°--------> by central angle
m ACB=360°-128°-----> m ACB=232°
∠x=(1/2)*[m ACB-m AB]
∠x=(1/2)*[232-128]-----> ∠x=(1/2)*104°-----> ∠x=52°

the answer is
∠ x is 52°

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.