A 25.12
B 31.4
C 78.5
D 157
Explanation: Area = πr² = 3.14 × 25 = 78.5.
Explanation: a² + b² = 9 + 16 = 25.
Explanation: 12% of 250 = 0.12 × 250 = 30.
A 6x + 2
B 6x - 2
C 4x + 2
D 8x + 2
Explanation: 4x - 8 + 2x + 6 = 6x - 2. Wait, that\'s -2, not +2. Let me recalculate: 4x-8+2x+6 = 6x-2.
Explanation: 0.25 = 25/100 = 1/4.
Explanation: Perimeter = 2(l+w) = 24, so l+w = 12. Width = 12-8 = 4.
Explanation: 3/5 + 2/5 = 5/5 = 1.
Explanation: 15² = 15 × 15 = 225.
Explanation: x = 10, so 2x = 20.
Explanation: Average = (5+10+15+20+25)/5 = 75/5 = 15.
Explanation: 50% of 90 = 0.50 × 90 = 45.
Explanation: Area = base × height = 10 × 4 = 40.
Explanation: 3x = 9, so x = 3.
Explanation: 0.25x = 20, so x = 80.
Explanation: Volume = l × w × h = 5 × 3 × 4 = 60.
Explanation: 7 × 8 = 56, minus 6 = 50.
Explanation: x²y = 4 × 3 = 12.
Explanation: 1/3 + 1/6 = 2/6 + 1/6 = 3/6 = 1/2.
Explanation: Perimeter = 5 + 7 + 8 = 20.