Answer:
x = 16
m<Y = 34°
Explanation:
∆XYZ is an isosceles ∆. An isosceles ∆ has two equal sides, as well as the bases of the isosceles triangle are congruent. In this case, therefore:
<X = <Z
(6x - 23)° = (4x + 9)
Solve for x
6x - 23 = 4x + 9
Collect like terms
6x - 4x = 23 + 9
2x = 32
Divide both sides by 2
x = 16
m<Y = 180° - (m<X + m<Z) (sum of ∆)
m<Y = 180 - ((6x - 23) + (4x + 9))
Plug in the value of x
m<Y = 180 - ((6(16) - 23) + (4(16) + 9))
m<Y = 180 - (73 + 73)
m<Y = 34°