125 ×(287 +8 ) + 287 × 875 =
=125 × 287 + 125× 8 + 287× 875=
= 287 × (125 + 875) + 125× 8 =
= 287 × 1000 + 1000=
= 1000× (287+1) = 288000
25 ×(4+399) + 399×75=
=25×4 + 25×399 + 399×75=
= 100 + 399 ×(25+75)=
= 100 + 399 × 100=
= 100× (1 +399)=
= 100×400=40000
48×11 -11×16 +32×19=
= 11×(48-16) + 32×19=
= 11×32 + 32×19=
= 32× (11+19)=
= 32×30 = 960
35²+ 65 × 35 = 35 ×(35+65) = 35×100=3500
74² - 74×64 = 74×(74-64) = 74×10=740
45×37 -45×23 + 14×55 =
= 45 × (37-23) + 14×55=
= 45×14 + 14×55 =
= 14×(45+55) = 14×100=1400
63×22 +37×39 +17×63 =
= 63×(22+17) + 37× 39=
= 63×39 + 37×39 =
= 39×(63+37) = 39×100= 3900