Insert brackets into the following to make them correct

27-4+2²:4=18

4x2+3-1=19

4=3²+1:5=6

3+2x6-3=27

7+4-9:3=8

6:2+4x2=11

3=1²:4=4

12+20:4²=2

7+7-18:6²=23

For the first one: i don't know ... i think it can't be done.

for the second one, it is : 4 * (2 + 3) - 1 = 19

for the third one, it is 4 + ((3² + 1) : 5) = 6

for the fourth one, it is : (3 + 2) * 6 - 3 = 27

for the fifth one, it is : 7 + 4 - (9 : 3) = 8

for the sixth one, it is : (6 : 2) + (4 * 2) = 11

for the seventh one, it is : (3 + 1) ² : 4 = 4

for the eight one, it is : (12 + 20) : 4² = 2

for the ninth one, it is : 7 + (7 - 18 : 6) ² = 23