How do you simplify $2 - 5 (3 t - 4)$ $2 - 5(3t - 4)$ ?

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Answer 1 · 2015-11-19T15:05:58

$22 - 15 t$ $22-15t$

the 5 multiplies everything inside the brackets so you have:

$2 - (5 \times 3 t - 5 \times 4)$ $2 - ( 5 times 3t - 5 times 4)$

$2 - (15 t - 20)$ $2 - ( 15t -20)$

But that is not the end of it! You have a minus in front of the bracket.
This is the same as multiplying everything inside the brackets by (-1).

By the way, another way of looking at ' plus ' is as 'put with'; and at subtract as 'remove from':

Now we have :

$2 - 1 (15 t - 20)$ $2 -1(15t-20)$

Just think about the $- 1 (15 t - 20)$ $-1(15t-20)$ on its own for now

We have:

$(- 1 \times 15 t) - (- 1 \times 20)$ $(-1 times 15t) - (-1 times 20)$

$(- 15 t) - (- 20)$ $(-15t)-(-20)$

Negative times negative give you a positive so we have
$- 15 t + 20$ $-15t + 20$

so $2 - (15 t - 20)$ $2 - ( 15t -20)$ becomes $\times 2 - 15 t + 20$ $color(white)(xx)2-15t+20$

regrouping gives

$- 15 t + 2 + 20$ $-15t +2+20$

$- 15 t + 22$ $-15t+22$ which is the same as $22 - 15 t$ $22-15t$

How do you simplify 2−5(3t−4)2 - 5(3t - 4)?