[b]Positive and negative numbers are called directed numbers[/b]
[img src='https://res.cloudinary.com/deylrqt2d/image/upload/v1484439665/mathsimage_1_mejhxm.gif']
(this is a number line)
An example of a [b]positive[/b] number is [b]4[/b]
An example of a [b]negative[/b] number is [b]-6[/b]
If I have the number [b]-4[/b] on the number line, and I move [b]6[/b] to the right, I will get [b]2[/b]. This is addition.
If I have the number [b]10[/b] on the number line, and I move [b]9[/b] to the right, I will get [b]1[/b]. This is called subtraction.
[hr]
If a question has one or more consecutive signs [+ or -], it should be cancelled down to one.
[table]
[tr]
[td style='padding:5px;border:1px solid #222;']Double Symbol[/td][td style='padding:5px;border:1px solid #222;']What it cancels to[/td]
[/tr]
[tr]
[td]++[/td][td]+[/td]
[/tr]
[tr]
[td]+-[/td][td]-[/td]
[/tr]
[tr]
[td]-+[/td][td]-[/td]
[/tr]
[tr]
[td]--[/td][td]+[/td]
[/tr]
[/table]
[b]The same consecutive signs make a '+'[/b]
[b]Different consecutive signs make a '-'[/b]
[h3]Multiplication, Division, Addition and Subtraction[/h3]
[table]
[tr]
[td style='padding:5px;border:1px solid #222;']Double Symbol[/td][td style='padding:5px;border:1px solid #222;']Resultant (+ or -):[/td]
[/tr]
[tr]
[td]+[i]x[/i] [multiply] +[i]x[/i][/td][td]+[i]x[/i][/td]
[/tr]
[tr]
[td]+[i]x[/i] [multiply] -[i]x[/i][/td][td]-[i]x[/i][/td]
[/tr]
[tr]
[td]-[i]x[/i] [multiply] +[i]x[/i][/td][td]-[i]x[/i][/td]
[/tr]
[tr]
[td]-[i]x[/i] [multiply] -[i]x[/i][/td][td]+[i]x[/i][/td]
[/tr]
[/table]
[highlight]
[b]2 like signs give a positive.
2 unlike signs give a negative.[/b]
[/highlight]
[h3]Examples[/h3]
[ol]
[li](-7)[squared] = -7 [multiply] -7 = +49[/li]
[li]4 [multiply] (-7) [divide] (-2) = +14[/li]
[li]20 [divide] (-2) [divide] 5 [multiply] (-4) = +8[/li]
[li]-25 [divide] -5 = 5[/li]
[/ol]
