Question

a)\(\frac{2x+4}{10}+\frac{2-x}{15}\)

b)\(\frac{3x}{10}+\frac{2x-1}{15}+\frac{2-x}{20}\)

c)\(\frac{x+1}{2x-2}+\frac{x^2+3}{2-2x^2}\)

d)\(\frac{1-2x}{2x}+\frac{2x}{2x-1}+\frac{1}{2x-2x^2}\)

e)\(\frac{x}{xy-y^2}+\frac{2x-y}{xy-x^2}\)

f)\(\frac{x^2}{x^2-4x}+\frac{6}{6-3x}+\frac{1}{x+2}\)

Answer 1

\(a,\frac{2x+4}{10}+\frac{2-x}{15}=\frac{\left(2x+4\right).3}{10.3}+\frac{\left(2-x\right).2}{15.2}\)

\(=\frac{6x+12}{30}+\frac{4-2x}{30}=\frac{6x+12+4-2x}{30}=\frac{4x+16}{30}\)

\(=\frac{4.\left(x+4\right)}{30}=\frac{2\left(x+4\right)}{15}\)

\(b,\frac{3x}{10}+\frac{2x-1}{15}+\frac{2-x}{20}=\frac{3x.6}{10.6}+\frac{\left(2x-1\right).4}{15.4}+\frac{\left(2-x\right).3}{20.3}\)

\(=\frac{18x}{60}+\frac{8x-4}{60}+\frac{6-3x}{60}=\frac{18x+8x-4+6-3x}{60}=\frac{23x+2}{60}\)

\(c,\frac{x+1}{2x-2}+\frac{x^2+3}{2-2x^2}=\frac{x+1}{2\left(x-1\right)}+\frac{x^2+3}{2\left(1-x^2\right)}=\frac{x+1}{2\left(x-1\right)}+\frac{-x^2-3}{2\left(x^2-1\right)}\)

\(=\frac{x+1}{2\left(x-1\right)}+\frac{-x^2-3}{2\left(x-1\right)\left(x+1\right)}\)\(=\frac{\left(x+1\right)\left(x+1\right)}{2\left(x-1\right)\left(x+1\right)}+\frac{-x^2-3}{2\left(x-1\right)\left(x+1\right)}\)

\(=\frac{x^2+2x+1-x^2-3}{2\left(x-1\right)\left(x+1\right)}=\frac{2x-2}{2\left(x-1\right)\left(x+1\right)}=\frac{2\left(x-1\right)}{2\left(x-1\right)\left(x+1\right)}\)\(=\frac{1}{x+1}\)