Michael 24 Nov 2015, 10:03
Is your answer to exercise 4 on Equivalent Fractions correct? If you multiply by minus on the bottom must you not also multiply by minus on top? Substituting real numbers for the algebraic terms does not work out!!
Tried the examples on the above page.
X
Is your answer to exercise 4 on Equivalent Fractions correct? If you multiply by minus on the bottom must you not also multiply by minus on top? Substituting real numbers for the algebraic terms does not work out!!
Relevant page <a href="/factoring-fractions/5-equivalent-fractions.php">5. Equivalent Fractions</a> What I've done so far Tried the examples on the above page.
Murray 25 Nov 2015, 04:18
Hi Michael
Good question. I have modified the solution on that page and I hope it makes sense now why I multiply the bottom of the fraction by minus, but not the top.
As for substituting, let's try `x = 2` and `y = 5`
In the original question:
`\text{LHS} = \frac{2^2 - 5^2}{5 - 2} = \frac{4 - 25}{3} = -\frac{21}{3} = -7`
RHS (the final answer) `= -2 - 5 = -7`
Hope that makes sense
Regards
Murray Bourne
X
Hi Michael
Good question. I have modified the solution on that page and I hope it makes sense now why I multiply the bottom of the fraction by minus, but not the top.
As for substituting, let's try `x = 2` and `y = 5`
In the original question:
`\text{LHS} = \frac{2^2 - 5^2}{5 - 2} = \frac{4 - 25}{3} = -\frac{21}{3} = -7`
RHS (the final answer) `= -2 - 5 = -7`
Hope that makes sense
Regards
Murray BourneX
Thanks for your help, as always
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