Question

1. (10x - 11)° (3x - 2)° (3x + 1)°
2. (3x - 5)° (7x + 5)°

Explanation:

Step1: Solve Problem 8 (Triangle Angle Sum)

The sum of angles in a triangle is \(180^\circ\). So, \((10x - 11)+(3x + 1)+(3x - 2)=180\).
Combine like terms: \(10x+3x+3x - 11 + 1 - 2 = 180\) → \(16x - 12 = 180\).
Add 12 to both sides: \(16x = 192\).
Divide by 16: \(x = 12\).

Step2: Solve Problem 9 (Right Triangle Angle Sum)

In a right triangle, the sum of angles is \(180^\circ\), and one angle is \(90^\circ\). So, \((7x + 5)+(3x - 5)+90 = 180\).
Combine like terms: \(7x+3x + 5 - 5 + 90 = 180\) → \(10x + 90 = 180\).
Subtract 90: \(10x = 90\).
Divide by 10: \(x = 9\).

Answer:

Problem 8: \(x = 12\)
Problem 9: \(x = 9\)