What do you call the drugs that bind to the receptor

What will come in the place of question mark (?) in the given expression?

√(? - 212) - 84 = 81 - 13 X 9

Evaluate: 18 ÷ 3 × 4 + 6 − 5

7(1/2) – 3(5/6) = ? − 2(7/12)

`2(1/3)` + `4(1/4)` + `4(2/3)` + `8(7/6)` + ? = `4(3/5)xx4(1/2)`

8⁹ ÷ 512 × (1/64) = (2³)^?

What should come in place of the question mark (?) in the following question?

2 – [6 – {3 + (–4 + 5 + 1) × 8} + 12] = ?

The value of 15 × 14 – 30 + (3² + 17) is:

1440 ÷ 12 + 540 ÷ √36 + ? = 180 * 3

[(15)³ × (8)²] ÷ (90 × 6) = ?²

What will come in place of the question mark (?) in the following question?

24.30% of 372.32 = ?