What approximate value will come in place of the question

Determine the value of ‘a’ if a = √529 + √1444

(21 × 51 + 81)/(9 × 14 - 30) = ?

What value should come in the place of (?) in the following questions?

(√1225 × 14) ÷ 5 + 95 × 55 = ?

118 × 6 + 13 + 83 = ?

12% of 450 + 16% of 1500 = ?

What value should come in the place of (?) in the following questions?

70% of 240 + 75% of ? = 45 * 55 ÷ 5

56 × 18 + ? × 21 – 49 × 12 = 63 × 26 

9 × 4⁰ × 24² × 18² = ?²

What value should come in the place of (?) in the following questions?

21² + 14 × 23 – 28 × 15 = ?