Question

solve 6th question
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Answer 1

Answer:

6) a) 31×32=992

b) 31×29 = 899

c)31×31=961

Answer 2

6.c

$31 \times 31 = (31) {}^{2} = 30 ^{2} + 2 \times 1 \times 30 + 1 {}^{2} = 900 + 60 + 1 = 961$

b.

$31 \times 29 = (30 + 1) \times (30 - 1) = 30 {}^{2} - 1 {}^{2} = 900 - 1 = 899$

a.

$31 \times 32 = (30 + 1) \times (30 + 2) = 30 {}^{2} + (1 + 2) \times 30 + 1 \times 2 = 900 + 90 + 2 = 992$