Question

{[(x+3)•3+3]•3+3}:3+4=20

Answer 1

{[(x+3)•3+3]•3+3}:3+4=20
{[(x+3)•3+3]•3+3}:3=20-4
{[(x+3)•3+3]•3+3}:3=16
[(x+3)•3+3]•3+3=16×3
[(x+3)•3+3]•3+3=48
[(x+3)•3+3]•3=48-3
[(x+3)•3+3]•3=45
(x+3)•3+3=45:3
(x+3)•3+3=15
(x+3)•3=15-3
(x+3)•3=12
x+3=12:3
x+3=4
x=4-3
x=1

Bafta!! :3

Answer 2

$\Big\{\big[(\text{x}+3)\cdot3+3\big]\cdot3+3\Big\}:3+4=20\\ \\ \Big\{\big[(\text{x}+3)\cdot3+3\big]\cdot3+3\Big\}:3 = 20-4 \\ \\ {\big[(\text{x}+3)\cdot3+3\big]\cdot3+3\Big\}:3 = 16 \\ \\ \big[(\text{x}+3)\cdot3+3\big]\cdot 3+3 = 16\cdot 3 \\ \\\big[(\text{x}+3)\cdot3+3\big]\cdot3+3 = 48 \\ \\ \big[(\text{x}+3)\cdot3+3\big]\cdot3 = 48-3 \\ \\\big[(\text{x}+3)\cdot3+3\big]\cdot3 = 45 \\ \\ (\text{x}+3)\cdot3+3 = 45:3 \\ \\ (\text{x}+3)\cdot3+3 = 15 \\ \\ (\text{x}+3)\cdot3 = 15-3$

$(\text{x}+3)\cdot3 = 12 \\ \\ \text{x}+3 = 12:3 \\ \\ \text{x}+3 = 4 \\ \\ \text{x} = 4-3 \\ \\ \boxed{\text{x} = 1}$