tolong kerjakan nomor 3 ,4 ,5,dan 7

3.)
2p - 2 = 4p + 10
2p - 4p = 10 + 2
-2p = 12
p = 12/-2
p = -6

4)
3/4 - 5p = -3p + 4
-5p + 3p = 4 - 3/4
-2p = 13/4
p = - 13/8

5)
2 - 1/4(3p-1) = 3 - 3/2(2p-1)
2 -  3/4p - 1/4 = 3 - 3p - 3/2
 -3/4p + 3p = 3 - 3/2 - 2 + 1/4
9/4p =  -1/4
p = -1/4 : 9/4
p = -1/9

7)
3x - y = 3 ............. x1(dikali)
x - 3y = 9 ............ x3(dikali)

3x - y = 3
3x - 9y = 27
------------------ -
8y = -24
y = -24/8
y = -3

substitusi

x - 3y = 9
x = 9 + 3y
x = 9 + 3(-3)
x = 9 + (-9)
x = 0