Answer:
9. x = 5
10. m∠Y = 34°
Explanation:
9.
Remember that congruent sides have congruent angles as well. That means 9x + 1 will be shown up in our equation twice. And as always, all angles in a triangle add up to 180.
2(9x + 1) + 88 = 180
18x + 2 + 88 = 180
18x + 90 = 180
18x = 90
x = 5
10.
The same concept applies here in question 10. Congruent angles and sides match each other. Therefore,
Step 1:
6x - 23 = 4x + 9
2x - 23 = 9
2x = 32
x = 16
Step 2:
Now that you have found x, plug it back into the given equations and find the other angle.
6(16) - 23 = 73
4(16) + 9 = 73
180 - (73)(2) = 34