Answer
4a. True for all b, 0=0
4b. No solution
Work Step by Step
4a.
$3(4b-2)=-6+12b$
Expand: $12b-6=-6+12b$
Add 6 to both sides: $12b-6+6=-6+12b+6$
Simplify: $12b=12b$
Subtract 12b from both sides: $12b-12b=12b-12b$
Simplify: $0=0$
Both sides are equal: True for all b
4b.
$2x+7=-1(3-2x)$
Expand: $2x+7=-3+2x$
Subtract 7 from both sides: $2x+7-7=-3+2x-7$
Simplify: $2x=2x-10$
Subtract 2x form both sides: $2x-2x=2x-10-2x$
Simplify: $0=-10$
The sides are not equal: No solution