Answer:
y=99, z=81
Explanation:
the angle above y is corresponding to 81, so if you substitute 81 in that place then it'll be angles on a straight line;
81 + y =180
(add like terms)
y =180 - 81
=99.
thus, y is 99. Once you do that, y and z are on a straight line so you solve for x using the formula for angles on a straight line;
y + (6z - 87)
(substitute y with 99)
99 + 6z - 87 =180
6z + 12 =180
(add like terms)
6z =180-12
6z =168
(divide both sides by six)
6z /6= 168/6
z = 28
(then you solve everything that was in the bracket for z)
(6z - 87)
(substitute z with 28)
=6 × 28 - 87
=168 - 87
=81
therefore, y =99 and z =81