Explain in complete sentences and demonstrate how to add:
\[\frac{ x-5 }{ 2x } \frac{ x+1 }{ 2x }\]
the two fractions are over each other @SolomonZelman
when you add fractions with the same denominator, only the numerator changes while the denominator remains the same. Add like terms in the numerator and you will get two times a number minus four, which is going to be over two times the number. IDK, ain't good at explaining math using sentences.
could you demonstrate?
\[\frac{x-5}{2x}+\frac{x+1}{2x}~~~~~->\]\[\frac{(x-5)+(x+1)}{2x}\]\[\frac{2x+4}{2x}\]
ohhhh i get it so the denominator doesn't change.
then reduce it,\[\frac{2x+4}{2x}~~~->~~~\frac{2(x+2)}{2x}~~~_>~~~\frac{x+2}{x}\] And yes the denominator stays the same.
ok i see hold on ill brb
K
k back
I"m here for a couple minutes or so....
ok so thats how you do it
Perform the subtraction: [(x-5)/2x] - [x/(x+3)] Discuss and identify any possible restrictions that exist in the resulting rational expression.
\[\frac{ x-5 }{ 2x }\]
minus
\[\frac{ x }{ x+3 }\]
demonstrate or sentences?
both, like the first question
I am not good at wrting sentences, but I can show you the math....
ok
\[\frac{x-5}{2x}~-~\frac{x}{x+3}\]\[\frac{x \color{red} {\times (x+3)}}{2x\color{red} {\times (x+3)}}~-~\frac{x \color{red} {\times 2x}}{(x+3) \color{red} {\times 2x} }\]
\[\frac{(x^2+3x)}{(2x^2+3x)}~-~\frac{(2x^2)}{(2x^2+3x)}\]
\[\frac{(x^2+3x)-(2x^2)}{(2x^2+3x)}\]
\[\frac{(-x^2+3x)}{(2x^2+3x)}\]
hmm
so you cross multiply?
no, I find the common denominator, doing it just like with any normal fraction, except that I am finding the common denominator between binomials and variables.
ohhh ok
any possible restrictions that are in the resulting expression?
@SolomonZelman
the denominator cannot equal zero, so \[\color{blue} {2x^2+3x≠0}\]\[\color{blue} {2x^2+3x\color{red} {+0}≠0}\]plug it inside the quadratic formula. \[\color{blue} {\frac{-3±\sqrt{3^2+(4 \times 2 \times 0)}}{2 \times 2}}\]\[\color{blue} {\frac{-3±\sqrt{9}}{4}}\]\[\color{blue} {\frac{-3±3}{4}}\]\[\color{blue} {x≠ 0~~~~~~~~~~or~~~~~~~~x≠ -1\frac{1}{2}}\]
thanks.
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