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markcr June 2nd, 2014 12:27 PM

simplifying with fractions
 
Hi

Another very basic problem...

How do you treat the x when multiplying it by a fraction? (in order to remove the brackets?)

y-4 = 1/2(x+2)


Thanks in advance.

Mark

greg1313 June 2nd, 2014 01:02 PM

Multiplying both sides by 2 gives 2y - 8 = x + 2.

perfect_world June 2nd, 2014 03:19 PM

$\displaystyle y-4=\frac { \left( x+2 \right) }{ 2 } \\ \\ 2\cdot y-2\cdot 4=\frac { \left( x+2 \right) }{ 2 } \cdot 2\\ \\ 2y-8=x+2\\ \\ x=2y-8-2\\ \\ x=2y-10=2\left( y-5 \right)$

skipjack June 3rd, 2014 12:22 AM

Quote:

Originally Posted by markcr (Post 196102)
How do you treat the x when multiplying it by a fraction?

1/2x = x/2, so 1/2(x + 2) = x/2 + 1.

markcr June 3rd, 2014 12:36 AM

Thanks everyone!

Mark

markcr June 3rd, 2014 01:07 PM

mmm...now what if it's a negative fraction:

y – 4 = -1/2 (x+2)

Denis June 3rd, 2014 01:22 PM

Quote:

Originally Posted by markcr (Post 196215)
mmm...now what if it's a negative fraction:
y – 4 = -1/2 (x+2)

Just multiply by -1:
-y + 4 = 1/2(x+2)

Make it clearer:
-y + 4 = (x+2) / 2


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