Question

If a=x−3,b=3x and x=2,find the value of 4ab

Answer 1

`\begin{gathered} a=x-3 \\ b=3x \\ x=2 \end{gathered}`

Substitute in the given expression (4ab) the variables (a and b) by its given values:

`4ab=4(x-3)(3x)`

Substitute in the expresion above the x by 2 and evaluate:

`\begin{gathered} 4(2-3)(3*2) \\ =4(-1)(6) \\ =-24 \end{gathered}`Then, the value of 4ab is -24