Couple of algebra questions?

Question

Anyone who gets 4 or more right, gets best answer :D

#1) 1/2(6)(18 + x) = 90

#2) 6y = 120/360xy

Solve for x and y :]

#3) 2x - 3y + 53 = 180

x - 5y = 53

#4) y = 2x - 3

5y = 6x +49

#5) 3y + 3 all over 3 =7y - 9 all over y

#6) 4 over y = y over 6

Answer 1

1) 1/2(6)(18 + x) = 90

54 + 3x= 90

3x= 36

x=12

#4) y = 2x - 3

5y = 6x +49

4x=64

x = 16

y = 29

#5) 3y + 3 all over 3 =7y - 9 all over y

y^2 + y = 7y -9

y^2 -6y + 9 = 0

(y-3)(y-3) therefore y = 3

#6) 4 over y = y over 6

24 = y^2

y = sq rt 24

y = 2sq rt 6

Answer 2

1) x = 12

#2) x = 18

#3) x = 68, y = 3

#4) x = 16, y = 29