Question

замени суммы произведениями.100×5+100×0,100×4+50×4+9×4,400×2+90×2+9×2,60×8+60×4,5×40+2×40,200×1+200×2

Answer 1

100×5
4(100+50+9)=4×159
2×(400+90+9)=2×499
60(8+4,5)=60×12,5
40(5+2)=40×7
200(1+2)=20×3