7.9x6.74-(7.43-0.69)x7.9(简便)

问题描述:

7.9x6.74-(7.43-0.69)x7.9(简便)

原式=7.9(6.74-7.43+0.69)=7.9(7.43-7.43)=0

7.9x6.74-(7.43-0.69)x7.9
=7.9x(6.74-7.43+0.69)
=7.9x(6.43+0.31-7.43+0.69)
=7.9x(6.43-7.43+0.69+0.31)
=7.9x(-1+1)
=0

=7.9*(6.74+0.69-7.43) =7.9*0 =0

7.9x6.74-(7.43-0.69)x7.9
=7.9x[6.74-(7.43-0.69)]
=7.9x(6.74+0.69-7.43)
=7.9x(7.43-7.43)
=7.9x0
=0

7.9x6.74-(7.43-0.69)x7.9
=7.9x(6.74-7.43+0.69)
=7.9x0
=0