Tính:
A = 1/2 - 1/2² + 1/2³ - 1/2⁴ + ... + 1/2⁹⁹ - 1/2¹⁰⁰
Tính:
A=( 1/2 - 1/3 ).( 1/2 - 1/5 ).( 1/2 - 1/7 )...( 1/2 - 1/99 )
Tính:
A=( 1/2 - 1/3 ).( 1/2 - 1/5 ).( 1/2 - 1/7 )...( 1/2 - 1/99 )
.·´¯`(>▂<)´¯`·.
tính:
a)1/(1+√2) + 1/(√2+√3) +....+ 1/(√99+√n)
b) 1/(2+√2) + 1/(3√2+2√3) +....+ 1((n+1)√2018+2018√(n+1))
a) bằng 9 nha bạn
b) thì mik ko bik làm.
Đúng thì bạn tim giúp mik nha bạn. Thx bạn
Thực hiện phép tính:
a) 5- 2( 1/2)2
b) (2-1/2)*(-3/4+1/2)
Thực hiện phép tính:
a) (-2).(-2).(-2)
b) (-0,5).(-0,5);
c) \(\frac{1}{2}.\frac{1}{2}.\frac{1}{2}.\frac{1}{2}.\)
a) \((-2).(-2).(-2) =4.(-2) = -8\)
b) \((-0,5).(-0,5) = 0,25\)
c)
\(\begin{array}{l}\frac{1}{2}.\frac{1}{2}.\frac{1}{2}.\frac{1}{2}\\ = \frac{{1.1.1.1}}{{2.2.2.2}}\\ = \frac{1}{{16}}\end{array}\)
thực hiện phép tính:
a, (2x + 1)2 - 4x (x - 1)
b, (x - 2) (x + 2) - (x - 1)2
a. \(\left(2x+1\right)^2-4x\left(x-1\right)=4x^2+4x+1-4x^2+4x=8x+1\)
b. \(\left(x-2\right)\left(x+2\right)-\left(x-1\right)^2=x^2-4-x^2+2x-1=2x-5\)
a)\((2x+1)^2-4x(x-1)=4x^2+4x+1-4x^2+4x\)
=\(8x+ 1\)
b)\((X-2)(x+2)-(x-1)^2=X^2-4-(x^2-2x+1)\)
=\(X^2-4-x^2+2x-1=2x-5\)
a: \(\left(2x+1\right)^2-4x\left(x-1\right)\)
\(=4x^2+4x+1-4x^2+4x\)
=8x+1
b: \(\left(x-2\right)\left(x+2\right)-\left(x-1\right)^2\)
\(=x^2-4-x^2+2x-1\)
=2x-5
Tính:
a, 3/4 * 2/9 + 1/3 = b, 1/4 : 1/3 - 1/2 =
a: =6/36+1/3=1/6+1/3=1/6+2/6=3/6=1/2
b: =3/4-1/2=3/4-2/4=1/4
\(a,\dfrac{3}{4}\times\dfrac{2}{9}+\dfrac{1}{3}=\dfrac{1}{6}+\dfrac{2}{6}=\dfrac{3}{6}=\dfrac{1}{2}\\ b,\dfrac{1}{4}:\dfrac{1}{3}-\dfrac{1}{2}=\dfrac{1}{4}\times\dfrac{3}{1}-\dfrac{2}{4}=\dfrac{3}{4}-\dfrac{2}{4}=\dfrac{1}{4}\)
a,34×29+13=16+26=36=12b,14:13−12=14×31−24=34−24=14
Thực hiện phép tính:
a, 5/17 + -5/34 . 2/5
b, 1/2 . 5/6 + 2/3 . 3/4
c, ( -2/5 + 1/3 ) . ( 3/2 - 3/7 )
d, ( 1+ 1/2 ) . ( 1+ 1/3 ) . ( 1+ 1/4 )
Thực hiện phép tính:
a, 5/17 + -5/34 . 2/5
b, 1/2 . 5/6 + 2/3 . 3/4
c, ( -2/5 + 1/3 ) . ( 3/2 - 3/7 )
d, ( 1+ 1/2 ) . ( 1+ 1/3 ) . ( 1+ 1/4 )
a. \(\dfrac{5}{17}+\dfrac{-5}{34}.\dfrac{2}{5}\)
= \(\dfrac{5}{17}+\dfrac{1}{-17}\)
= \(\dfrac{5}{17}+\dfrac{-1}{17}\)
= \(\dfrac{4}{17}\)
b. \(\dfrac{1}{2}.\dfrac{5}{6}+\dfrac{2}{3}.\dfrac{3}{4}\)
= \(\dfrac{5}{12}+\dfrac{1}{2}\)
= \(\dfrac{5}{12}+\dfrac{6}{12}\)
= \(\dfrac{11}{12}\)
c. \(\left(\dfrac{-2}{5}+\dfrac{1}{3}\right).\left(\dfrac{3}{2}-\dfrac{3}{7}\right)\)
= \(\left(\dfrac{-6}{15}+\dfrac{5}{15}\right).\left(\dfrac{21}{14}-\dfrac{6}{14}\right)\)
= \(\dfrac{-1}{15}.\dfrac{15}{14}\)
= \(\dfrac{-1}{14}\)
d. \(\left(1+\dfrac{1}{2}\right).\left(1+\dfrac{1}{3}\right).\left(1+\dfrac{1}{4}\right)\)
= \(\left(\dfrac{2}{2}+\dfrac{1}{2}\right).\left(\dfrac{3}{3}+\dfrac{1}{3}\right).\left(\dfrac{4}{4}+\dfrac{1}{4}\right)\)
= \(\dfrac{3}{2}.\dfrac{4}{3}.\dfrac{5}{4}\)
= \(\dfrac{5}{2}\)
Thực hiện phép tính:
a, 5/17 + -5/34 . 2/5
b, 1/2 . 5/6 + 2/3 . 3/4
c, ( -2/5 + 1/3 ) . ( 3/2 - 3/7 )
d, ( 1+ 1/2 ) . ( 1+ 1/3 ) . ( 1+ 1/4 )
a: \(=\dfrac{5}{34}\cdot\dfrac{2}{5}=\dfrac{2}{34}=\dfrac{1}{17}\)
b: \(=\dfrac{5}{12}+\dfrac{6}{12}=\dfrac{11}{12}\)
c: \(=\dfrac{-6+5}{15}\cdot\dfrac{21-6}{15}=-\dfrac{1}{15}\)