tính
a) \(199.\left(15-17\right)-199.\left(-17+5\right)\)
b) \(-39.\left(5-99\right)+99.\left(10-39\right)\)
c) \(79.89-79.\left(-11\right)\)
tính
a) \(-39.\left(5-99\right)+99.\left(10-39\right)\)
b) \(79.89-49.\left(-11\right)\)
a) \(-39.\left(5-99\right)+99.\left(10-39\right)\)
\(=-39.5+39.99+99.10-99.39\)
\(=\left(39.99-99.39\right)-39.5+99.10\)
\(=0-195+990\)
\(=-195+990\)
\(=795\)
b)\(79.89-49.\left(-11\right)\)
\(=7031+539\)
\(=7570\)
-39 (5 - 99) + 99 (10 - 39)
= -39 . (-94) + 99 . (-29)
= 3666 + (-2871)
= 795
79 . 89 - 49 . (-11)
= 7031 - (-539)
= 7031 + 539
= 7570
Học tốt!!!
\(a.35-17+2017-35+\left(-2017\right)\)
\(b.37+\left(-17\right)-37+77\)
\(c.-\left(-219\right)+\left(-219\right)-401+12\)
\(d.|-85|-\left(-3\right).15\)
\(e.11.107+11.18-25.11\)
\(f.115-\left(-85\right)+53-\left(-500+53\right)\)
\(g.\left(-18\right)+\left(-31\right)+98+|-18|+\left(-69\right)\)
\(h.17.\left(15-16\right)+16.\left(17-20\right)\)
\(k.15.\left(-176\right)+15.76+100.15\)
\(l.79.89-79.\left(-11\right)-100.79\)
\(m.153.177-153.77+100.\left(-77\right)\)
\(n.-69.|-45|-31.|45|\)
\(o.\left(-29\right).\left(85-47\right)-85.\left(47-29\right)\)
\(p.\left(-167\right).\left(67-34\right)-67.\left(34-167\right)\)
cứ từ từ mà làm cũng đc
Chắc đợi mai lm nha nhiều z tết năm sau mới lm xong
MAI LÀM LÀ XONG LUÔN RỒI!!
Cậu để chữ cứ từ lm đê lm j z
Tính:
a) M = \(1\left(\frac{-6}{13}+\frac{15}{26}-\frac{47}{39}-\frac{1}{78}\right):\left(99\frac{17}{65}-100\frac{5}{52}+\frac{1}{130}\right).\)
b) V = \(\frac{\left(\frac{3}{5}-0,435+\frac{1}{200}\right):\left(-0,04\right)}{30,75+\frac{1}{12}+3\frac{1}{6}}\)
tìm x,biết:
a)\(\frac{2}{\left(x+2\right)\left(x+4\right)}+\frac{4}{\left(x+4\right)\left(x+8\right)}+\frac{6}{\left(x+8\right)\left(x+14\right)}=\frac{x}{\left(x+2\right)\left(x+14\right)}\)
b)\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
c)\(\left(x+2\right)^2=\frac{38}{25}+\frac{9}{10}-\frac{11}{15}+\frac{13}{21}-\frac{15}{28}+\frac{17}{36}-...+\frac{197}{4851}-\frac{199}{4950}\)
giúp tớ với,huhu
tính nhanh
a, \(\frac{-2}{5}\cdot\left(\frac{5}{17}-\frac{9}{15}\right)-\frac{2}{5}\cdot\frac{2}{17}+\frac{-2}{5}\)
b, \(\frac{1}{5}\cdot\left(\frac{4}{13}-\frac{9}{11}\right)+\frac{1}{3}\left(\frac{9}{13}-\frac{4}{22}\right)\)
c, \(\left(\frac{1}{2}+1\right)\cdot\left(\frac{1}{3}+1\right)\cdot\left(\frac{1}{4}+1\right)\cdot...\cdot\left(\frac{1}{99}+1\right)\)
d, \(\left(1-\frac{1}{2}\right)\cdot\left(1-\frac{1}{3}\right)\cdot\left(1-\frac{1}{4}\right)\cdot...\cdot\left(1-\frac{1}{100}\right)\)
Mk ko biết lm nhưng cứ k thoải mái nha
SORRY
3.Tính hợp lí:
a,\(\frac{17}{5}.\frac{-31}{125}.\frac{1}{2}.\frac{10}{17}.\frac{-1}{2^3}\)
b,\(\left(\frac{11}{4}.\frac{5}{9}-\frac{4}{9}.\frac{11}{4}\right).\frac{8}{33}\)
c,\(\left(\frac{17}{28}+\frac{18}{29}-\frac{19}{30}-\frac{20}{31}\right).\left(\frac{-5}{12}+\frac{1}{4}+\frac{1}{6}\right)\)
4.Tìm tích:
a,\(\left(\frac{1}{2}+1\right)\left(\frac{1}{3}+1\right).....\left(\frac{1}{99}+1\right)\)
b,\(\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right).....\left(\frac{1}{100}-1\right)\)
c,\(\frac{3}{2^2}.\frac{8}{3^2}.\frac{15}{4^2}....\frac{899}{30^2}\)
AI CÒN THỨC THÌ GIÚP MIK VS,MIK ĐANG CẦN GẤP
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a} đây là biểu thức gì\)
a) A=\(\left(\frac{-5}{11}\right).\frac{7}{15}.\left(\frac{11}{-5}\right).\left(-30\right)\)
b) B=\(\left(-\frac{1}{6}\right).\left(\frac{-15}{19}\right).\left(\frac{38}{45}\right)\)
c) C= \(\left(\frac{-5}{9}\right).\frac{3}{11}+\left(\frac{-13}{18}\right).\frac{3}{11}\)
d) D= \(\left(2\frac{2}{15}.\frac{9}{17}.\frac{3}{32}\right):\left(\frac{-3}{27}\right)\)
Tính nhanh
a,\(A=100^2-99^2+98^2-97^2+...+2^2-1^2\)
b,\(B=\left(20^2+18^2+...+2^2\right)-\left(19^2+17^2+....+3^2+1^2\right)\)
c,\(C=\frac{780^2-220^2}{125^2+150.125+75^2}\)
d,\(D=2.\left(a+5\right).\left(a+4\right)-\left(a+5\right)^2-\left(a^2-9a-17\right)\)với a=99
a/ A = 1002 - 992 + 982 -...+22 - 12
= (1002 - 992) + (982 - 972) +...+ (22 - 12)
= 199 + 195 + 191 + ... + 1
= (\(\frac{199-1}{4}+1\))(\(\frac{199+1}{2}\)) = 5050
b/ Y chang câu a luôn nha
c/ \(C=\frac{780^2-220^2}{125^2+150.125+75^2}=\frac{\left(780-220\right)\left(780+220\right)}{\left(125+75\right)^2}\)
\(=\frac{560.1000}{200^2}=14\)
d/ 2(a + 4)(a + 5) - (a + 5)2 - (a2 - 9a - 17)
= 17a + 32 = 17(a + 1) + 15 = 1700 + 15 = 1715
\(\left(\frac{1}{17}-1\right)\left(\frac{2}{17}-1\right)\left(\frac{3}{17}-1\right)...\left(\frac{99}{17}-1\right)\)
???????????????????? chúc bạn giả bài này nhé chịu thôi
\(\left(\frac{1}{17}-1\right)\left(\frac{2}{17}-1\right)\left(\frac{3}{17}-1\right)....\left(\frac{99}{17}-1\right)\)
= \(\left(\frac{1}{17}-\frac{17}{17}\right)\left(\frac{2}{17}-\frac{17}{17}\right)\left(\frac{3}{17}-\frac{17}{17}\right).......\left(\frac{99}{17}-\frac{17}{17}\right)\)
= \(\left(\frac{-16}{17}\right)\left(\frac{-15}{17}\right)\left(\frac{-14}{17}\right).......\left(\frac{82}{17}\right)\)
= \(\frac{\left(-16\right).\left(-15\right).\left(-14\right)......82}{17}\)