`a) A=4\sqrt{(25x)/4}-8/3\sqrt{(9x)/4}-4/(3x)\sqrt{(9x^2)/64}` `(x>=0)`
`A=4. \sqrt{(5/2)^2 x}-8/3\sqrt{(3/2)^2 x}-4/(3x). \sqrt{((3x)/8)^2}`
`A=4. 5/2\sqrt{x}-8/3. 3/2\sqrt{x}-4/(3x). (3x)/8`
`A=10\sqrt{x}-4\sqrt{x}-1/2`
`A=6\sqrt{x}-1/2`
`b) B=y/2+3/4\sqrt{1-4y+4y^2}-1/2` `(y<=1/2)`
`B=y/2+3/4 \sqrt{(1-2y)^2}+1/2`
`B=y/2+3/4|1-2y|+1/2`
`B=y/2+3/4(1-2y)+1/2`
`B=y/2+3/4-3/2 y+1/2`
`B=-y+5/4`
