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Math questions

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**1**of**1**[ 5 posts ]

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

[366 / (-6) - (-6)] / (-11)

I simplified it as

[366 / 0] / - 11

how can you divide by zero?

Apparently the answer is 5.

Jsmitheh wrote:

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

[366 / (-6) - (-6)] / (-11)

I simplified it as

[366 / 0] / - 11

how can you divide by zero?

Apparently the answer is 5.

Okay,

21 + 32 / (-4) + (-6) = 21 -(32/4) -6 = 21 -8 -6 = 21 -14 = 7;

[366 / (-6) - (-6)]/ (-11) = [(366/-6) +6]/-11) = [-(366/6) +6]/(-11) =

[-61+6]/(-11) = (-55)/(-11) = 55/11 = 5;

Hope this helps!

Jsmitheh wrote:

I found an old maths book the other day and decided to look at it. For some reason these incredibly easy questions make no sense to me.

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

i have not much time to describe for now, but it is an example of the priority of process of of the operands.

i see it as this:

21 + (32 / (-4) + (-6))

now 32/-4 = -8

so 21-8 is 13.

and if you add -6 to 13 you get 7.

Jsmitheh wrote:

I found an old maths book the other day and decided to look at it. For some reason these incredibly easy questions make no sense to me.

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

21 + 32 / (-4) + (-6)

I simplified it as

53 / -10

-5.3

But apparently it's 7, how is this?

You grouped the terms incorrectly. This should be read as:

21 + (32/-4) + (-6)

which comes out to 21 - 8 - 6 = 7

In general / and * are done before + and - in a complex expression.

If there is any doubt, parentheses should be used.

For example what is 8/2*4? It is either 8/2 * 4 ( = 16) or 8/(2*4) ( = 1 ). The parens should be used to resolve ambiguity.

ruveyn

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