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 Question from geraldine: simplify: -3(x-7)

Hi Geraldine,

What you need to use here is the Distributive Rule which says that for any numbers $a, b$ and $c$

$a ( b + c ) = a \times b + a \times c.$

Thus, for example you can calculate $-3 (8 - 6)$ as $-3 (8 - 6) = -3 \times 2 = -6$ or use the distributive to get

$-3(8 - 6) = (-3)(8 + [-6]) = (-3)\times 8 + (-3)\times(-6) = (-24) + (18) = -6.$

For another example, more like your problem

$-5 ( 8 - y) = (-5) \times 8 + (-5) \times (-y) = -40 + 5y.$

Now try your example and write back if you still need help,
Penny

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