a)
[tex]3(x - 5) = - 18 \\ 3x - 15 = - 18 \\ 3x = - 18 + 15 \\ 3x = - 3 \\ x = - 3 \div 3 \\ x = - 1[/tex]
b)
[tex]6(x - 2) = 24 \\ 6x - 12 = 24 \div 6x = 24 + 12 \\ 6x = 36 \\ x = 36 \div 6 \\ x = 6[/tex]
c) -7(x-3)=-49
-7x+21=-49
-7x=-49-21
-7x=-70 |•(-1)
7x=70
x=70:7
x= 10