Thực hiện nay phép tính cùng rút gọn:
a) (x + 1 over 2x + 6 + 2x + 3 over x(x + 3)) ;
b) (1 – 3x over 2x + 3x – 2 over 2x – 1 + 3x – 2 over 2x – 4x^2) ;Quảng cáo
c) (x over (x – 2y)(z – x) + 2y over (2y – z)(x – 2y) + z over (z – x)(2y – z)) .
(eqalign và a),,x + 1 over 2x + 6 + 2x + 3 over xleft( x + 3 ight) cr & ,,,,, = x + 1 over 2left( x + 3 ight) + 2x + 3 over xleft( x + 3 ight) cr & ,,,,, = left( x + 1 ight)x over 2left( x + 3 ight)x + 2left( 2x + 3 ight) over 2left( x + 3 ight)x cr và ,,,,, = x^2 + x + 4x + 6 over 2left( x + 3 ight)x = x^2 + 5x + 6 over 2left( x + 3 ight)x cr & ,,,,, = left( x + 3 ight)left( x + 2 ight) over 2left( x + 3 ight)x = x + 2 over 2x cr và b),,1 – 3x over 2x + 3x – 2 over 2x – 1 + 3x – 2 over 2x – 4x^2 cr và ,,,,, = left( 1 – 3x ight) over 2x + – left( 3x – 2 ight) over 1 – 2x + 3x – 2 over 2xleft( 1 – 2x ight) cr và ,,,,, = left( 1 – 3x ight)left( 1 – 2x ight) over 2xleft( 1 – 2x ight) + – left( 3x – 2 ight).2x over 2xleft( 1 – 2x ight) + 3x – 2 over 2xleft( 1 – 2x ight) cr & ,,,,, = 1 – 2x – 3x + 6x^2 – 6x^2 + 4x + 3x – 2 over 2xleft( 1 – 2x ight) cr & ,,,,, = 2x – 1 over 2xleft( 1 – 2x ight) = – left( 1 – 2x ight) over 2xleft( 1 – 2x ight) = – 1 over 2x cr & c),,x over left( x – 2y ight)left( z – x ight) + 2y over left( 2y – z ight)left( x – 2y ight) + z over left( z – x ight)left( 2y – z ight) cr và ,,,,, = xleft( 2y – z ight) over left( x – 2y ight)left( z – x ight)left( 2y – z ight) + 2yleft( z – x ight) over left( x – 2y ight)left( z – x ight)left( 2y – z ight) + zleft( x – 2y ight) over left( x – 2y ight)left( z – x ight)left( 2y – z ight) cr & ,,,,, = 2xy – xz + 2yz – 2xy + zx – 2yz over left( x – 2y ight)left( z – x ight)left( 2y – z ight) cr và ,,,,, = 0 over left( x – 2y ight)left( z – x ight)left( 2y – z ight) = 0 cr )
