a) `4x^2-9-x(2x-3)=0`
`4x^2 - 2x^2 + 3x - 9 = 0`
`2x^2 + 3x - 9 = 0`
`2x^2 - 3x + 6x - 9 =0`
`x(2x - 3) + 3(2x - 3) = 0`
`(2x-3)(x+3)=0`
⇒ \(\left[ \begin{array}{l}2x-3=0\\x+3=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=3/2\\x=-3\end{array} \right.\)
b) `4x^2 - 12x+9=0`
`4x^2 - 6x - 6x + 9 =0`
`2x(2x - 3) - 3(2x - 3)=0`
`(2x-3)(2x-3)=0`
`(2x-3)^2 = 0`
⇒ `2x-3 = 0`
`2x = 3`
`x=3/2`
