Question

calculați mintal
${31}^{2}$
${ 51}^{2}$
$49 {}^{2}$
$99 {}^{2}$
$26 {}^{2}$
$101 {}^{2}$
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Answer 1

Răspuns:

31^2=(30+1)^2=900+60+1=961

51^2=(50+1)^2=2500+100+1=2601

49^2=(40+9)^2=1600+18*40+81=1600+720+81=2401

99^2=(90+9)^2=8100+18*90+81=8100+1620+81=9801

26^2=(20+6)^2=400+12*20+36=400+240+36=676

101^2=(100+1)^2=10000+200+1=10201

Explicație pas cu pas: