Answer:
x = 9
Step-by-step explanation:
The triangle given is an isosceles triangle because it has two equal sides. By implication, the two base angles that are opposite the two equal sides are equal to each other.
Therefore,
80° + 2(m<2) = 180° (sum of triangle theorem)
80 + 2(5x + 5) = 180
80 + 10x + 10 = 180
Add like terms
90 + 10x = 180
90 + 10x - 90 = 180 - 90 (substraction property of equality)
10x = 90
10x/10 = 90/10 (division property of equality)
x = 9