3. Ifodalarning qiymatini sharhlab hisoblang va ularni taqqoslang. a) 587 · 324 □ 945 · 135; b) 329 · 276 □ 478 · 158; d) 128 · 621 □ 273 · 354; e) 482 · 235 □ 345 · 274.

Ko‘paytuvchilarni qulay qo‘shiluvchilarga ajratib, ko‘paytmalarni hisoblaymiz.

a) \(587 \cdot 324 = 587 \cdot (300+24)=176\,100+14\,088=190\,188\). \(945 \cdot 135=945\cdot(100+35)=94\,500+33\,075=127\,575\). Demak, \(190\,188 > 127\,575\), shuning uchun 587 · 324 > 945 · 135.

b) \(329\cdot276=329\cdot(200+76)=65\,800+25\,004=90\,804\). \(478\cdot158=478\cdot(160-2)=76\,480-956=75\,524\). Demak, 329 · 276 > 478 · 158.

d) \(128\cdot621=621\cdot(100+28)=62\,100+17\,388=79\,488\). \(273\cdot354=273\cdot(350+4)=95\,550+1\,092=96\,642\). Demak, 128 · 621 < 273 · 354.

e) \(482\cdot235=482\cdot(200+35)=96\,400+16\,870=113\,270\). \(345\cdot274=345\cdot(300-26)=103\,500-8\,970=94\,530\). Demak, 482 · 235 > 345 · 274.