Solve following equations:
1) x2 = 16
2) \(\sqrt{16}=x\)
3) 9x - 3x = 4
4) 2y + 3x = 3x
5) 7 ( a + 3 ) / ( a + 9 ) = 3
1) x = \(\pm \mbox{ } 4\)
2) x = 4
3) 6x = 4 | :6
x = 2/3
4) 2y = 0 | : 2
y = 0
5) 7(a + 3) = 3a + 27 | distribute
7a + 21 = 3a + 27 | - 21
7a = 3a + 6 | - 3a
4a = 6 | : 4
a = 3/2
