a)4x+1/3x-5 + 2x/12x-20

b) 3x-1/x^2+4x+3 - x+6/2x^2+7x+1

Simplify and state restrictions on the variable

Please help

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- Nov 2nd 2008, 07:43 AMeuclid2adding and subtracting rational expressions
a)4x+1/3x-5 + 2x/12x-20

b) 3x-1/x^2+4x+3 - x+6/2x^2+7x+1

Simplify and state restrictions on the variable

Please help - Nov 2nd 2008, 07:56 AMGlaysher
(a) First factorise and cancel where possible

4x+1/3x-5 + 2x/12x-20 = 4x+1/3x-5 + 2x/4(3x-5) = 4x+1/3x-5 + x/2(3x-5)

Then multiply the top and bottom of each fraction so that they have the same denominator

= 2(4x+1)/2(3x-5) + 2x/4(3x-5)

Then add the fractions together

= (8x+2+2x)/2(3x-5) = (10x+2)/2(3x-5)

Finally factorise and cancel down if possible

= 2(5x+1)/2(3x-5) = (5x+1)/(3x-5)

(b) similar - Nov 2nd 2008, 08:29 AMeuclid2
what would be the restrictions or how do you get the restrictions?

- Nov 2nd 2008, 09:39 AMHallsofIvy