Answer:
99°
Explanation:
We know that angles on a straight line add up to 180° so we can set up an equation to find the value of x.
In an equation it's important to do the operation you want to on both sides because if you do an operation on one side only you will end up changing the whole equation and that will make the value of x wrong so its an important rule to remember.
8x - 13 + 7x - 17 = 180
→ Simplify
15x - 30 = 180
→ Add 30 to both sides to isolate 15x
15x = 210
→ Divide both sides by 15 to isolate x
x = 14
But we are not finished, the specifies us to find ∠MON and we have only found the value of x so we have to substitute x back into 8x - 13 to find the value of ∠MON
8x - 13
→ Substitute x = 14 back into into the expression
8 × 14 - 13
→ Simplify
112 - 13 = 99
So the value of ∠MON is 99°