Find the square of $3 a + 7 b$

9 a^{2} + 42 a b + 49 b^{2}

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9 a^{2} + 40 a b + 49 b^{2}

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18 a^{2} + 42 a b + 98 b^{2}

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18 a^{2} + 40 a b + 98 b^{2}

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Solution

The correct option is A $9 a^{2} + 42 a b + 49 b^{2}$
Squaring,
$(3 a + 7 b)^{2}$
$= (3 a)^{2} + 2 (3 a) (7 b) + (7 b)^{2}$
$= 9 a^{2} + 42 a b + 14 b^{2}$

Suggest Corrections

Similar questions

(3 a - 7 b - c)^{2}

= 9 a^{2} + 49 b^{2} + c^{2} - 42 a b + 14 b c - 6 c a

If 3a - 7b = 26 and ab = 5, then the value of 9a² + 49b².

Factorise:

$4 a^{2} - 49 b^{2} + 2 a - 7 b$

(3 a - \frac{1}{2}) (3 a - \frac{1}{2})

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