8th Class Mathematics Sample Paper Mathematics Sample Paper - 10

  • question_answer
                                   Find the value of \[x,\text{ 10000}x\text{ }={{\left( 9982 \right)}^{2}}-{{\left( 18 \right)}^{2}}\]

    Answer:

    R.H.S     \[={{\left( 9982 \right)}^{2}}-{{\left( 18 \right)}^{2}}\]
    \[=\left( 9982+18 \right)\left( 9982-18 \right)~\]
    \[[Since,\text{ }{{a}^{2}}-{{b}^{2}}=\left( a+b \right)\left( a-b \right)]\]
    \[=\left( 10000 \right)\times \left( 9964 \right)~\]
    L.H.S \[=\left( 10000 \right)\text{ }\times \text{ }x\]
    Comparing L.H.S. and R.H.S, we get
    \[10000x\text{ }=\text{ }10000\times 9964\]
    or x \[=\frac{10000\times 9964}{10000}=9964\]
         


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