I need to solve from x

To begin solving for X, we need it to be an equation rather than an expression. This I what I mean:

(-6x+51) = ?

We need to figure out what comes after the equal sign in order to solve for X.

The angle measures inside a triangle always add up to 180°. We are given that Angle P = 80° and Angle Q = 43°. With this given information it makes it simple to figure out the missing angle measure inside the triangle:

80+43= 123

180-123= 57

So the unknown angle measure in that triangle is 57°. Now we will subtract 57° from 180°. Why? Because a straight line is 180° and that's exactly the angle measure of the side that Angle R and Angle Q are on (hope that isn't to confusing )

With that being said, (-6x+51)° plus 57° would equal 180°. We don't need the 57 in the equation to solve for X though, because now we now that (-6x+57)= 123. That's because 180-57= 123, so we now know the outside angle measure next to Angle R equals 123°.

We can finally solve for X:

-6x+51= 123

(subtract 51 from both sides to even out the equation. We subtract because that's the inverse operation of addition)

-6x=72

(now we simply divide -6 on both sides, because division is the inverse operation of multiplication)

x= -12

(Hope this helps and wasn't to confusing for you to understand :). Let me know if you have any other questions about this problem.)

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

b