Question

How to find (67×68) without multiply directly.

Answer 1

$\huge{\underline{\boxed{\mathfrak{AnSwEr}}}}$

(67×68) = (60+7)(60+8)

therefore, using the identity 4

$(x + a)(x + b) = x {}^{2} + (a + b)x + ab$

$\rule{190}1$

So according to your question:-

$\sf60 {}^{2} + (7 + 8)60 + 7 \times 8$

$3600+ 487+ 56$

$\implies$ 4143 ans.