tolong dibantu nomer 6,7 dan 9

7) 4-3x = 10-x
    -3x+x = 10-4
    -2x = 6
    x = -3
9) 5(x-2) + 5 = x+7
    5x-10+5 = x+7
    5x-5 = x+7
    5x-x = 7+5
    4x = 12
    x = 3