thuc hien phep tinh (100- 1 ) (100-2)..........(100-3)
1:" thuc hien phep tinh : (-1)+2-3+4-....-99+100
khong thuc hien phep tinh , hay so sanh : 99 x 99 va 98 x 100
Ta có: 99x99=99x(98+1) = 99x98+99
98x100= 98x(99+1) = 98x99+98
Ta có: 98x99=98x99 mà 99> 98 => 99x99>98x100
Thuc hien phep nhan rut gon roi tinh gia tri bieu thuc
B)x(x^2-y)-x^2(x+y)+y(x^2-x) tai x=1/2 va y=-100
=x^3-xy-x^3-x^2y+x^2y--xy
=-2xy
thay x=1\2 va y bang 100 vao Bta duoc
B= -2.1\2.100=-100
thuc hien phep tinh
a) S1=2+2^2+2^3+...+2^90
b)S2= (-2) +(-2)^2 +(-2)^3+...(-2)^100
c)S3=2^100-2^99-2^98-2^97-...-2^2-2-1
d)S4=1-3+5-7+...+2001-2003+2005-
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
thuc hien phep cac phep tinh sau:
a, (1-1/2).(1-1/3).(1-1/4)...(1-1/100)
b, (1+1/1.3).(1+1/2.4).(1+1/3.5)...(1+1/99.101)
Thuc hien phep tinh
A, 3/7 + 1/2 - (-3)/70
B, 3/5 + -1/25 - 35/100
C, 5/12 - 3/-16 + 3/4
D, 5/15 + 4/-12 + 1/7 - 1/-6
a,3/7 +1/2-[-3]/70
=13/14 -[-3]/70
=65/70 -[-3]/70
=34/35
b,3/5+-1/25 -35/100
=14/25 - 35/100
=56 /100 -35/100
= 21/100
c ,5/12 -3/-16+3/4
=29/48 +3/4
= 29/48 +36/48
=65/48
d, 5/15 +4/-12 +1/7 -1/-6
= 1/3 +1/-3 +1/7-1/-6
=0+1/7-1/-6
= 13/42
A.\(\dfrac{3}{7}+\dfrac{1}{2}+\dfrac{\left(-3\right)}{70}\)
=\([\dfrac{30}{70}+\dfrac{\left(-3\right)}{70}]\)+\(\dfrac{1}{2}\)
= \(\dfrac{27}{70}+\dfrac{35}{70}\)
=\(\dfrac{62}{70}=\dfrac{31}{35}\)
B.\(\dfrac{3}{5}+\dfrac{-1}{25}-\dfrac{35}{100}\)
=\(\dfrac{60}{100}+\dfrac{-4}{100}-\dfrac{35}{100}\)
=\(\dfrac{60+\left(-4\right)-35}{100}\)
=\(\dfrac{21}{100}\)
C.\(\dfrac{5}{12}-\dfrac{3}{-16}+\dfrac{3}{4}\)
=\(\left(\dfrac{5}{12}+\dfrac{9}{12}\right)-\dfrac{-3}{16}\)
=\(\dfrac{7}{6}-\dfrac{-3}{16}\)
=\(\dfrac{56}{48}-\dfrac{-9}{48}\)=\(\dfrac{65}{48}\)
D.\(\dfrac{5}{15}+\dfrac{4}{-12}+\dfrac{1}{7}-\dfrac{1}{-6}\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+(\dfrac{-2}{6}-\dfrac{-1}{6})\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{-1}{6}\)
=\((\dfrac{1}{3}+\dfrac{-1}{6})+\dfrac{1}{7}\)
=\(\dfrac{1}{6}+\dfrac{1}{7}\)=\(\dfrac{13}{42}\)
bai 1: Thuc hien phep tinh
a) 75/100 + 18/21 + 19/32 + 1/4 + 3/21 + 13/32
b) 22/5 + 51/9 + 11/4 + 3/5 + 1/3 + 1/4
1a
75/100+18/21+19/32+1/4+3/21+13/32
= 3/4 +6/7+19/32+1/4+1/7+13/32
= (3/4+1/4)+(19/32+13/32)+(6/7+1/7)
= 1+1+1=3
1b
22/5+51/9+11/4+3/5+1/3+1/4
=22/5+17/3+11/4+3/5+1/3+1/4
=(22/5+3/5)+(17/3+1/3)+(11/4+1/4)
=25/5+18/3+12/4
=5+6+3
=14
ko thuc hien phep tinh tong nao sao day chia het cho 8
a 100-40
b 80-16
b nha b
phép tính b chia hết cho 8 nha
K cho mik nha bn
so sanh A va B
A=10^30
B=2^100
ai nhanh minh tich cho
khong thuc hien phep tinh nha
\(A=10^{30}=\left(10^3\right)^{10}=1000^{10}\)
\(B=2^{100}=\left(2^{10}\right)^{10}=1024^{10}\)
Do: 1000 < 1024 nên 100010 < 102410
Hay: A < B
Ta có:
\(A=10^{3\cdot10}=100^{10}\)
\(B=2^{10\cdot10}=1024^{10}\)
khi bỏ mũ \(^{10}\)ra thì ta còn 100 và 1024 bạn nhé.
Vì 100<1024 nên \(100^{10}< 1024^{10}\) hay \(10^{30}< 2^{100}\Leftrightarrow A< B\)
mk không chắc lắm nhé.