Hi there! The answer is 18.
First we need to solve the first equation for b.
[tex]4b - 3 = 2b[/tex]
Subtract 2b from both sides.
[tex]2b - 3 = 0[/tex]
Add 3 to both sides.
[tex]2b = 3[/tex]
Divide both sides by 2.
[tex]b = \frac{3}{2} = 1 \frac{1}{2} [/tex]
Now we can plug our value of b into the second expression.
[tex]12b = 12 \times 1 \frac{1}{2} = 18[/tex]
