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852+752+652+552−452−352−252-152
=(852-152)+(752-252)+(652-352)+(552-452)
=70.100+50.100+30.100+10.100
=160.100=16000
a) \(A=123\left(123+154\right)+77^2\)
\(A=123^2+\left(123.154\right)+77^2=\left(123+77\right)^2=200^2=400\)
b) \(B=3^{24}-\left(2^{47}+1\right)\left(9^6-1\right)\)
\(B=3^{24}-\left(3^{12}-1\right)\left(3^{12}+1\right)\)
\(B=3^{24}-3^{24}+1=1\)
c) \(C=85^2+75^2+65^2+55^2-45^2-35^2-25^2-15^2\)
\(C=\left(85^2-15^2\right)+\left(75^2-25^2\right)+\left(65^2-35^2\right)+\left(55^2-45^2\right)\)
\(C=\left(85+15\right)\left(85-15\right)+\left(75+25\right)\left(75-25\right)+\left(65+35\right)\left(65-35\right)\left(55+45\right)\left(55-45\right)\)
\(C=100\left(60+50+40+30+20+10\right)\)
\(C=100.210=21000\)
B=\(3^{24}-\left(27^4+1\right)\left(9^6+1\right)=-1062883\)A=123(123+154)+772=123.277+772=34843
C=\(85^2+75^2+65^2+55^2-45^2-35^2-25^2-15^2=16000\)
a) \(85^2+75^2+65^2+55^2-45^2-35^2-25^2-15^2\)
\(=\left(85^2-15^2\right)+\left(75^2-25^2\right)+\left(65^2-35^2\right)+\left(55^2-45^2\right)\)
\(=\left(85-15\right)\left(85+15\right)+\left(75-25\right)\left(75+25\right)+\left(65-35\right)\left(65+35\right)+\left(55-45\right)\left(55+45\right)\)
\(=70.100+50.100+30.100+10.100\)
\(=7000+5000+3000+1000\)
\(=16000\)
b) \(\frac{135^2+130.135+65^2}{135^2-65^2}\)
\(=\frac{135^2+2.60.135+65^2}{135^2-65^2}\)
\(=\frac{\left(135+65\right)^2}{\left(135-65\right)^2}\)
\(=\frac{200^2}{70^2}\) \(=\frac{200}{70}=\frac{20}{7}\)
a) \(A=85^2-45^2+75^2-35^2+65^2-25^2+55^2-15^2\)
\(A=\left(85-45\right)\left(85+45\right)+....+\left(55-15\right)\left(55+15\right)\)
\(A=40.130+40.110+40.90+40.70\)
\(A=40.\left(130+110+90+70\right)=40.400=16000\)
b) \(B=\left(1-2\right)\left(1+2\right)+\left(3-4\right)\left(3+4\right)+...+\left(2011-2012\right)\left(2011+2012\right)\)
\(B=-3-7-11-...-4023\)
\(B=-\left(3+7+11+...+4023\right)\)
\(B=-\dfrac{\left(3+4023\right)\left[\dfrac{\left(4023-3\right)}{4}+1\right]}{2}=2025078\)
(15+75)+(20+70)+(25+65)+(30+60)+(35+55)+(40+50)+45
= 90+90+90+90+90+90+45
= 90.6+45
= 540+45=585
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