Question

Rút gọn các biểu thức sau:

a) M=(71+x)-(-24+x)+(-35-x)

b) N=x-34-[(15+x)-(23-x)]

Answer 1

a/ M = (71+x)-(-24+x)+(-35-x) = 71 + x + 24 - x - 35 - x = (71 + 24 - 35) - x = 95 - 35 - x = 60 - x

b/ N=x-34-[(15+x)-(23-x)] = x - 34 - (15 + x - 23 + x) = x - 34 - (-8 + 2x) = x - 34 + 8 - 2x = -26 - x

Answer 2

\(a,M=\left(71+x\right)-\left(-24+x\right)+\left(-35-x\right)\)

        \(=71+x+24-x-35-x\)

        \(=60-x\)

\(b,N=x-34-\left[\left(15+x\right)-\left(23-x\right)\right]\)

       \(=x-34-\left(15+x-23+x\right)\)

       \(=x-34-15-x+23-x\)

       \(=-26-x\)

Answer 3

a) M=(71+x)-(-24+x)+(-35-x)

      = 71+x-(-24)-x+(-35)-x

      = (-24+71)+(-35)+(x-x-x)

      = 47+(-35)+(-x)

      = 12+(-x)

      = 12-x

 Vậy M=12-x