tính nhanh
c,93 ×107=
d,127 ²+146 ×127+73 ² 3.
Tính nhanh
A=20^2+18^2+16^2+.....+2^2-19^2-17^2-3^2-1
B=127^2+146×127+73^2
Tính:
a,A=127^2+146×127+73^2
b,B=9^8×2^8-(18^4-1)×(18^4+1)+(a+b)^2
c, C=(20^2+18^2+...+4^2+2^2)-(19^2+17^2+...+3^2+1)
Answer:
\(A=127^2+146.127+73^2\)
\(=127^2+2.127.73+73^2\)
\(=\left(127+73\right)^2\)
\(=200^2\)
\(=40000\)
\(B=9^8.2^8-\left(18^4-1\right)\left(18^4+1\right)\)
\(=\left(9.2\right)^8-[\left(18^4\right)^2-1]\)
\(=18^8-18^8+1\)
\(=1\)
\(C=\left(20^2+18^2+16^2+...+4^2+2^2\right)-\left(19^2+17^2+15^2+...+3^2+1^2\right)\)
\(=20^2+18^2+16^2+...+4^2+2^2-19^2-17^2-15^2-...-3^2-1^2\)
\(=\left(20^2-19^2\right)+\left(18^2-17^2\right)+...+\left(2^2-1^2\right)\)
\(=\left(20-19\right)\left(20+19\right)+\left(18-17\right)\left(18+17\right)+...+\left(2-1\right)+\left(2+1\right)\)
\(=1.39+1.35+...+1.3\)
\(=39+35+...+3\)
Số số hạng \(\frac{39-3}{4}+1=10\) số hạng
Tổng \(\frac{\left(39+3\right).10}{2}=210\)
1,tính nhanh giá trị các biểu thức sau
a , C= 1272 + 146 . 127 + 732
b, A = \(\frac{2006^3+1}{2006^2-2005}\) ; B =\(\frac{2006^3-1}{2006^2+2007}\)
ai nhanh mik tik cho
a, \(C=127^2+146.127+73^2\)
\(=127^2+2.127.73+73^2\)
\(=\left(127+73\right)^2\)
\(=200^2=40000\)
a, \(\frac{2006^3+1}{2006^2-2005}\)
\(=\frac{\left(2006+1\right)\left(2006^2-2006+1\right)}{2006^2-2005}=\frac{2007\left(2006^2-2005\right)}{2006^2-2005}=2007\)
\(\frac{2006^3-1}{2006^2+2007}\)
\(=\frac{\left(2006-1\right)\left(2006^2+2006+1\right)}{2006^2+2007}=\frac{2005\left(2006^2+2007\right)}{2006^2+2007}=2005\)
Chúc bạn học tốt.
Tính nhanh
C) 127^2 +146+127+732
127^2+146+127+732
=16129+146+127+732
=17134
Tính nhanh
C) 127^2 +146+127+732
= 127.127+127+19+127+127.5+97
= 127.134+19+81+16
= 17018+100+16
= 17134
Tính nhanh
( - 127 ) x 73 + 127 x ( -27 )
(-127) x 73+(-127) x 27
=(-127) . (73+27)
=(-127).100
=-12700
Rút gọn biểu thức sau:
a, x + 31 + ( -12 ) + 52
b, ( -35 ) - ( x + 23 ) + 61
c, 127 - ( 127 - x ) + 23
d, 107 - ( 107 + x - 23 )
a: x+31+40=x+71
b: =-35-x-23-61=-119-x
Rút gọn biểu thức:
a) x + 31 + (-12) + 52; b) (-35) - (x + 23) + 61;
c) 127- (127 - x) + 23; d) 107 - (107 + x - 23)
Áp dụng quy tắc dấu ngoặc rồi thực hiện các phép tính, ta thu được kết quả.
a) x + 71. b) 3 - x. c) x + 23. d) 23 - x
1. Tìm x:
a. 2x.(2x-1)^2 - 3x.(x+3).(x-3) - 4x.(x+1)^2 - x^3 = x^3 - 16.x^2 + 1
b. x.(x-2)^2 + 3x.(2x-1)^2 - 13.x^2 + 16.x^2 = 5x+2
2. Tính nhanh
a. 127^2 + 146 x 127 + 73^2
b. 9^8 x 2^8 - ( 18^4 - 1 ) x ( 18^4 + 1 )
help pls
Tính nhanh, dùng hằng đẳng thức thứ 1;2;3
a) 1272 + 146 . 127 + 732
b) 98 . 28 - (184 - 1)(184 + 1)
c) \(\frac{780^2-220^2}{125^2+150.125+75^2}\)
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= (127 + 73)2 = 2002 = 40000
b) 98 . 28 - (184 - 1)(184 + 1)
= (9.2)8 - 188 + 1
= 188 - 188 + 1 = 1
c) \(\frac{780^2-220^2}{125^2+150.125+75^2}=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2.75.125+75^2}=\frac{560.1000}{\left(125+75\right)^2}=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}=14\)
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= ( 127 + 73 )2
= 2002 = 40 000
b) 98.28 - ( 184 - 1 )( 184 + 1 )
= ( 9.2 )8 - [ ( 184 )2 - 12 ]
= 188 - 188 + 1
= 1
c) \(\frac{780^2-220^2}{125^2+150\cdot125+75^2}\)
\(=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2\cdot75\cdot125+75^2}\)
\(=\frac{560\cdot1000}{\left(125+75\right)^2}\)
\(=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}=14\)
Bài làm :
a) 1272 + 146.127 + 732
= 1272 + 2.73.127 + 732
= ( 127 + 73 )2
= 2002
= 40 000
b) 98.28 - ( 184 - 1 )( 184 + 1 )
= ( 9.2 )8 - [ ( 184 )2 - 12 ]
= 188 - 188 + 1
= 1
\(\text{c)}\frac{780^2-220^2}{125^2+150\cdot125+75^2}\)
\(=\frac{\left(780-220\right)\left(780+220\right)}{125^2+2\cdot75\cdot125+75^2}\)
\(=\frac{560\cdot1000}{\left(125+75\right)^2}\)
\(=\frac{560000}{200^2}\)
\(=\frac{560000}{40000}\)
\(=14\)