How do you simplify $7(0.2p+0.3q)+5(0.6p-q)$ ?

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Answer 1 · 2017-08-27T14:43:45

$4.4p-2.9q$

Introducing you to a really cool trick.

Do not like decimals so lets get rid of them.

Multiply everything by 1 but in the form of $color(red)(1=10/10)$

If we do the division by 10 at the end we would have the correct answer.

Note: Using an example suppose we had $10(a+b)$ . This is the same as $10a+10b$

So using the above principle:

$color(green)(color(red)(10/10)[color(white)(2/2)7(0.2p+0.3q)+5(0.6p-q)color(white)(2/2)]$

$color(green)(color(red)(1/10)[color(white)(2/2)color(white)("b")7(2p+3q)color(white)("bb")+5(6p-10q)color(white)(2/2)]$

$color(green)(color(red)(1/10)[color(white)(2/2)14p+21q+30p-50qcolor(white)(2/2)]$

$color(green)(color(red)(1/10)[color(white)(2/2)44p-29qcolor(white)(2/2)]$

$color(white)("bbbbb")color(green)(4.4p-2.9q)$

How do you simplify 7(0.2p+0.3q)+5(0.6p-q)7(0.2p+0.3q)+5(0.6p-q)?