Question

计算题 x^2-16分之x^2-5x+6除以4-x分之x-3乘4-x^2分之x^2+5x+4(x^2-16)分之(x^2

Answer 1

(x^2-5x+6)/(x^2-16)÷(x-3)/(4-x)×(x^2+5x+4)/(4-x^2)

=(x-2)(x-3)/(x+4)(x-4)×[-(x-4)]/(x-3)×(x+1)(x+4)/[-(x+2)(x-2)]

=(x+1)/(x+2)