thuc hien phep tinh:-39.(5-99)+99.(10-99)
thuc hien phep tinh:-39.(5-99)+99.(10-99)
thuc hien phep tinh:-39.(5-99)+99.(10-39) hay giai ra cho minh nhe
-39 x ( 5 - 99 ) + 99 x ( 10 - 39 )
= -39 x 5 - 39 x ( -99 ) + 99 x 10 - 99 x 39
= -39 x 5 + [ 39 x 99 - 99 x 39 ] + 99 x 10
= -39 x 5 + 99 x 10
= -39 x 5 + 198 x 5
= 5 x ( -39 + 198 )
= 5 x 159
= 795
-39.(5-99)+99.(10-39)
=-39.(-94)+99.(-29)
=3666+(-2871)
=795
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
1:" thuc hien phep tinh : (-1)+2-3+4-....-99+100
THUC HIEN PHEP TINH
1+1^3+1^4+... +1^98 +1^99
help me mik like
1 + 13 + 14 + ............. + 198 + 199 (98 số hạng)
= 1 + 1 + 1 + 1 + .......... + 1 (98 số hạng)
= 98 . 1
= 98
1) Tim A , biet :
(242 / 363 - 1616 / 2121) = 2 / 7 x A
2)Thuc hien phep tinh :
99 / 98 - 98 / 97 + 1 / 97 x 98
cac ban giup toi cau nay voi:
Thuc hien phep tinh(hop ly neu co the):
(10/99+11/199-12/299)x(1/2-1/3+-1/6)
mong cac ban giup minh nhanh voi a. Minh xin cam on
\(\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{1}{2}-\frac{1}{3}+-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times\left(\frac{3}{6}-\frac{2}{6}-\frac{1}{6}\right)\)
\(=\left(\frac{10}{99}+\frac{11}{199}-\frac{12}{299}\right)\times0\)
\(=0\)
thuc hien phep tinh\(\frac{1}{99\cdot97}-\frac{1}{97-95}-...-\frac{1}{3\cdot1}\)giải ra nha cần gấp nếu thấy đúng mk tick cho
\(\frac{1}{99.97}-\frac{1}{97.95}-...-\frac{1}{3.1}\)
\(\frac{1}{99}-\frac{1}{97}-\frac{1}{97}-\frac{1}{95}-...-\frac{1}{3}-1\)
\(\frac{1}{99}-1\)
\(-\frac{98}{99}\)
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-
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)