Explanation: x = 28/4 = 7.
Explanation: 3.5 × 2 = 7.
Explanation: Area = d²/2 = 100/2 = 50.
Explanation: x/4 = 4, so x = 16.
Explanation: 0.3 × 0.3 = 0.09.
Explanation: Radius = diameter/2 = 14/2 = 7.
Explanation: 2/3 × 45 = 90/3 = 30.
Explanation: Sum = n(n+1)/2 = 10(11)/2 = 55.
Explanation: Adding equations: 2x = 12, so x = 6.
Explanation: |-5 + 3| = |-2| = 2.
Explanation: 6 + 3y = 12, so 3y = 6, y = 2.
Explanation: 11 × 11 = 121.
Explanation: Area = ½(a+b)h = ½(6+10)(4) = ½(16)(4) = 32.
Explanation: 2³ × 2² = 2⁵ = 32.
Explanation: 3/5 = 24/x, so x = 40.
Explanation: 25 + 20 = 45.
Explanation: The slope is the coefficient of x, which is 3.
Explanation: a - b = 5 - (-3) = 5 + 3 = 8.