How do you evaluate $[(- 7 \times 8) - (- 15 \times 4)] - 3]$ $[( - 7\times 8) - ( - 15\times 4) ] - 3]$ ?

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Answer 1 · 2017-10-20T16:57:18

$4$ $4$

Let's take a look at this

$[(- 7 \times 8) - (- 15 \times 4)]$ $[(-7 xx 8) - (-15 xx 4)]$

We'll go through the "order of operations" (PEMDAS), starting with parentheses.

$[j (- 7 \times 8) - (- 15 \times 4) j]$ $[ color(white)(j) color(green)((-7 xx 8)) - color(red)((-15 xx 4)) color(white)(j) ]$

$- 7 \times 8$ $color(green)(-7 xx 8)$ simplifies to $- 56$ $color(green)(-56)$

$- 15 \times 4$ $color(red)(-15 xx 4)$ simplifies to $- 60$ $color(red)(-60)$

So, we have $[j (- 56) - (- 60) j]$ $[ color(white)(j) color(green)((-56)) - color(red)((-60)) color(white)(j) ]$

$- 56 - (- 60)$ $-56- (-60)$ is the same as $- 56 + 60$ $-56+60$ , which is $4$ $4$

So, now we are left with
$[j 4 j]$ $[ color(white)(j) 4 color(white)(j) ]$ or just $4$ $4$

How do you evaluate [(−7×8)−(−15×4)]−3][( - 7\times 8) - ( - 15\times 4) ] - 3] ?