Ответ:
Применяем формулы квадрата суммы и квадрата разности
[tex]\bf (a\pm b)^2=a^2\pm 2ab+b^2[/tex] .
[tex]\bf 71^2=(70+1)^2=70^2+2\cdot 70\cdot 1+1^2=4900+140+1=5041\\\\91^2=(90+1)^2=90^2+2\cdot 90\cdot 1+1^2=8100+180+1=8281\\\\69^2=(70-1)^2=70^2-2\cdot 70\cdot 1+1^2=4900-140+1=4761\\\\48^2=(50-2)^2=50^2-2\cdot 50\cdot 2+2^2=2500-200+4=2304\\\\85^2=(80+5)^2=80^2+2\cdot 80\cdot 5+5^2=6400+800+25=7225\\\\102^2=(100+2)^2=100^2+2\cdot 100\cdot 2+2^2=10000+400+4=10404[/tex]
Copyright © 2024 SCHOLAR.TIPS - All rights reserved.
Answers & Comments
Verified answer
Ответ:
Применяем формулы квадрата суммы и квадрата разности
[tex]\bf (a\pm b)^2=a^2\pm 2ab+b^2[/tex] .
[tex]\bf 71^2=(70+1)^2=70^2+2\cdot 70\cdot 1+1^2=4900+140+1=5041\\\\91^2=(90+1)^2=90^2+2\cdot 90\cdot 1+1^2=8100+180+1=8281\\\\69^2=(70-1)^2=70^2-2\cdot 70\cdot 1+1^2=4900-140+1=4761\\\\48^2=(50-2)^2=50^2-2\cdot 50\cdot 2+2^2=2500-200+4=2304\\\\85^2=(80+5)^2=80^2+2\cdot 80\cdot 5+5^2=6400+800+25=7225\\\\102^2=(100+2)^2=100^2+2\cdot 100\cdot 2+2^2=10000+400+4=10404[/tex]