(i)
![\[\mathbf{3}{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{5x}\text{ }\text{ }\mathbf{12}\text{ }=\text{ }\mathbf{0}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-f507f0da2ea3d04ca6b1ceb479f3f0af_l3.png "Rendered by QuickLaTeX.com")
Let us simplify the given expression,
![\[\begin{array}{*{35}{l}} 3{{x}^{2}}~\text{ }9x\text{ }+\text{ }4x\text{ }\text{ }12\text{ }=\text{ }0 \\ 3x\left( x\text{ }\text{ }3 \right)\text{ }+\text{ }4\left( x\text{ }\text{ }3 \right)\text{ }=\text{ }0 \\ \left( 3x\text{ }+\text{ }4 \right)\text{ }\left( x\text{ }\text{ }3 \right)\text{ }=0 \\ \end{array}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-4afcfd3b61885487b55409659d7cbb6d_l3.png "Rendered by QuickLaTeX.com")
So now,
![\[\begin{array}{*{35}{l}} \left( 3x\text{ }+\text{ }4 \right)\text{ }=\text{ }0\text{ }or\text{ }\left( x\text{ }\text{ }3 \right)\text{ }=0 \\ 3x\text{ }=\text{ }-4\text{ }or\text{ }x\text{ }=\text{ }3 \\ x\text{ }=\text{ }-4/3\text{ }or\text{ }x\text{ }=\text{ }3 \\ \end{array}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-02f923dd2781dcb9b5691443e04aeda2_l3.png "Rendered by QuickLaTeX.com")
∴ Value of x =
![\[-4/3,\text{ }3\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-f156886c285552fad6c5684ba9745b83_l3.png "Rendered by QuickLaTeX.com")
(ii)
![\[\mathbf{21}{{\mathbf{x}}^{\mathbf{2}}}~\text{ }\mathbf{8x}\text{ }\text{ }\mathbf{4}\text{ }=\text{ }\mathbf{0}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-eecceb5c1e7d8d2c9382f333675d36fb_l3.png "Rendered by QuickLaTeX.com")
Let us simplify the given expression,
![\[<span class="ql-right-eqno"> (1) </span><span class="ql-left-eqno"> </span><img src="https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-2e8e0683c7ed9477deefc9d1818d0e14_l3.png" height="126" width="406" class="ql-img-displayed-equation quicklatex-auto-format" alt="\begin{align*} & \begin{array}{*{35}{l}} 21{{x}^{2}}~\text{ }14x\text{ }+\text{ }6x\text{ }\text{ }4\text{ }=\text{ }0 \\ 7x\left( 3x\text{ }\text{ }2 \right)\text{ }+\text{ }2\left( 3x\text{ }\text{ }2 \right)\text{ }=\text{ }0 \\ \end{array} \\ & \left( 7x\text{ }+\text{ }2 \right)\text{ }\left( 3x\text{ }\text{ }2 \right)\text{ }=\text{ }0 \\ \end{align*}" title="Rendered by QuickLaTeX.com"/>\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-9b65554e0dc73a72f144b7464234b280_l3.png "Rendered by QuickLaTeX.com")
So now,
![\[\begin{array}{*{35}{l}} \left( 7x\text{ }+\text{ }2 \right)\text{ }=\text{ }0\text{ }or\text{ }\left( 3x\text{ }\text{ }2 \right)\text{ }=\text{ }0 \\ 7x\text{ }=\text{ }-2\text{ }or\text{ }3x\text{ }=\text{ }2 \\ x\text{ }=\text{ }-2/7\text{ }or\text{ }x\text{ }=\text{ }2/3 \\ \end{array}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-0f8effc3ca09c52f2a3cea792130aede_l3.png "Rendered by QuickLaTeX.com")
∴ Value of x =
![\[-2/7,\text{ }2/3\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-a7e5a7d924c887720ff12ade449e90b1_l3.png "Rendered by QuickLaTeX.com")
(i)
(i)
Let us simplify the given expression,
So now,
∴ Value of x =
(ii)
Let us simplify the given expression,
So now,
∴ Value of x =
