Question

I don’t get how I get the numerators to be -8-3 here

Answer 1

First, notice that:

`\begin{gathered} 10=5\cdot2,\text{ } \\ (2)/(2)=1. \end{gathered}`

Therefore:

`-(4)/(5)=-(4)/(5)\cdot1=-(4)/(5)((2)/(2))=-(4\cdot2)/(5\cdot2)=-(8)/(10)\text{.}`

That is how you go from -4/5 to -8/10.

Since -3/10 already has 10 as its denominator then it remains the same.

`-(8)/(10)-(3)/(10)=-(11)/(10)\text{.}`

Examples (negative numbers):

`\begin{gathered} -1-3=-(1+3)=-4, \\ 1-3=-2, \\ -1+3=2, \\ 1+3=4. \end{gathered}`
`-1+3=3-1=2.`
`\begin{gathered} -5+8=8-5=3, \\ -3+5=5-3=2. \end{gathered}`