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a. \(76^2-24^2=\left(76+24\right)\left(76-24\right)=100.52=5200\)
b. \(106^2+106.12+6^2=\left(106+6\right)^2=12544\)
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Lời giải:
$A=64^2-54^2=(64-54)(64+54)=10.118=1180$
$B=76^2+2.76.23+23^2=(76+23)^2=99^2=(100-1)^2=100^2-2.100+1$
$=10000-200+1=9801$
$C=88^2+62^2-38^2-12^2=(88^2-38^2)+(62^2-12^2)$
$=(88-38)(88+38)+(62-12)(62+12)$
$=50.126+50.74=50(126+74)=50.200=10000$
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\(76^2-24^2=\left(76-24\right)\left(76+24\right)=52.100=5200\)
\(24^2+48.76+76^2=24^2+2.24.76+76^2=\left(24+76\right)^2=100^2=10000\)
\(23,18.26+44.23,18=23,18\left(26+44\right)=23,18.70=1622,6\)
\(53.47=\left(50+3\right)\left(50-3\right)=50^2-3^2=2500-9=2491\)
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a) \(1,6^2+4.0,8.3,4+3,4^2=1,6^2+2.1,6.3,4+3,4^2=\left(1,6+3,4\right)^2=5^2=25\)
b) \(3^4.5^4-\left(15^2+1\right)\left(15^2-1\right)=15^4-15^4+1=1\)
c) \(76^2+38.48+24^2=76^2+2.38.24+24^2=\left(76+24\right)^2=100^2=10000\)
Câu C pải là 76 ^2 nha bn
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1. a) 762 + 242 + 48.76 = 242 + 2.24.76 + 762 = (24 + 76)2 = 1002 = 10000
b) 202.198 - 203.197 = (200 + 2)(200 - 2) - (200 + 3)(200 - 3) = (2002 - 22) - (2002 - 32) = 9 - 4 = 5
2 . x2 - 4x + 5 = x2 - 2.x.2 + 22 + 1 = (x - 2)2 + 1 .
(x - 2)2\(\ge0\)nên GTNN của x2 - 4x + 5 là : 0 + 1 = 1 tại : (x - 2)2 = 0 <=> x = 2
\(76^2+24^2+48\cdot76\)
\(=76^2+48+48\cdot76\)
\(=48\left(5776+76\right)\)
\(=48\cdot5852\)
\(=280896\)
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a) \(501^2=\left(500+1\right)^2=250000+1000+1=251001\)
b) \(99^2=\left(100-1\right)^2=10000-200+1=9801\)
c) \(76.42=\left(59+17\right)\left(59-17\right)=59^2-17^2=3481-289=3192\)
Bài làm :
\(501^2=\left(500+1\right)^2=250000+1000+1=251001\)
\(b,99^2=\left(100-1\right)^2=10000-200+1=9801\)
\(c,76.42=\left(59+17\right)\left(59-17\right)=59^2-17^2=3192\)
Học tốt
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a) 9992 - 1 = 9992 - 12 = (999 - 1).(999 + 1) = 998.1000 = 99800
b) 101.99 = (100+1).(100-1) = 1002 - 1 = 10000 - 1 = 9999
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Ta có : (x + 4)2 - (x + 1)(x - 1) = 16
<=> x2 + 8x + 16 - (x2 - 1) = 16
<=> x2 + 8x + 16 - x2 + 1 = 16
<=> 8x + 17 = 16
=> 8x = -1
=> x = \(-\frac{1}{8}\)
Ta có : x2 - 4x + 4 =0
<=> x2 - 2.x.2 + 22 = 0
<=> (x - 2)2 = 0
=> x - 2 = 0
=> x = 2
\(17^2+13^2+26.17\)
\(=13^2+2.13.17+17^2\)
\(=\left(13+17\right)^2\)
\(=20^2\)
\(=400\)
\(76^2-24^2\)
\(=\left(76-24\right)\left(76+24\right)\)
\(=52.100\)
\(=5200\)