Algebraic Expressions and Identities — MATHS STD 8 — Question
Gujarat BoardEnglish MediumSTD 8MATHSAlgebraic Expressions and Identities3 Marks
Question
$1.8 × 2.2$
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Answer
Here, we will use the identity $(a - b) (a + b) = a^2- b^2$
Let us consider the following expression:
$1.8 × 2.2$
$\because\frac{1.8+2.2}{2}=\frac{4}{2}=2,$therefore, we will write the above product as:
$1.8 × 2.2 = (2 - 0.2) (2 + 0.2)$
$= (2)^2- (0.2)^2$
$= 4 - 0.04$
$= 3.96$
Thus, the answer is $3.96$
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