How do you solve the equation
3(1+x)=-3(x+1)

x=-1

simplify: 3(x+1)=-3(x+1)

3x+3=-3x-3

minus 3 from each side to cancel out the -3:

3x=-3x-6

add 3x to each side to cancel out the -3x:

6x=-6

single out the x by dividing 6 from both sides:

x=-1

the correct answer is d

hope this