Question
$9.8 \times 10.2$
✓
Answer
Here, we will use the identity $(a-b)(a+b)=a^2-b^2$
Let us consider the following expression:
$9.8 \times 10.2$
$\because \frac{9.8+10.2}{2}=\frac{20}{2}=10, \text { t }$
$9.8 \times 10.2$
$=(10-0.2)(10+0.2)$
$=(10)^2-(0.2)^2$
$=100-0.04$
$=99.96$
$\because \frac{9.8+10.2}{2}=\frac{20}{2}=10 \text {, therefore, we will write the above product as: }$
Thus, the answer 99.96
Let us consider the following expression:
$9.8 \times 10.2$
$\because \frac{9.8+10.2}{2}=\frac{20}{2}=10, \text { t }$
$9.8 \times 10.2$
$=(10-0.2)(10+0.2)$
$=(10)^2-(0.2)^2$
$=100-0.04$
$=99.96$
$\because \frac{9.8+10.2}{2}=\frac{20}{2}=10 \text {, therefore, we will write the above product as: }$
Thus, the answer 99.96
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