solution using distributive property -25 * -31

We can split 31 as (30 + 1) in two groups.

Now according to the distributive property, multiply a number by a group of numbers added together, so we have;

$25\times 31\phantom{\rule{0ex}{0ex}}=25\left(30+1\right)\phantom{\rule{0ex}{0ex}}=25\times 30+25\times 1\phantom{\rule{0ex}{0ex}}=750+25\phantom{\rule{0ex}{0ex}}=775$

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