Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
x + 78 - 12 x 7= 987
x + 78 - 84 = 987
x + 78 = 987 + 84
x + 78 = 1071
x = 1071 - 78
x = 993
Kb nhaAikatsu Ichigo
\(\frac{1}{1.2.3}+\frac{1}{2.3.4}+...+\frac{1}{8.9.10}=\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{2.3}\right)+\frac{1}{2}.\left(\frac{1}{2.3}-\frac{1}{3.4}\right)+...+\frac{1}{2}.\left(\frac{1}{8.9}-\frac{1}{9.10}\right)\)
\(=\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{2.3}+\frac{1}{2.3}-\frac{1}{3.4}+...+\frac{1}{8.9}-\frac{1}{9.10}\right)\)
\(\frac{1}{2}.\left(\frac{1}{1.2}-\frac{1}{9.10}\right)=\frac{1}{2}.\frac{22}{45}=\frac{11}{45}\)
Đặt \(A=\frac{1}{1.2}+\frac{1}{2.3}+...+\frac{1}{99.100}\)
\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)
\(A=1-\frac{1}{100}\)
\(A=\frac{99}{100}\)
2\(\frac{2}{12}\)+ X = \(\frac{5}{7}\)+ \(\frac{8}{12}\)
\(\frac{13}{6}\)+ X=\(\frac{29}{21}\)
X= \(\frac{29}{21}\)- \(\frac{13}{6}\)
X=\(\frac{-11}{14}\)
\(|2^2_{12}\)\(+x=\frac{5}{7}+\frac{8}{12}\)
\(2+x=\frac{5}{7}+\frac{1}{2}\)
\(2+x=\frac{17}{14}\)
\(x=\frac{17}{14}-2\)
\(x=\frac{-11}{14}\)
a,71-(33+x)=26
33+x =71-26
33+x =45
x =45-33
x =12
b,(x+73)-26=76
x+73 =76+26
x+73 =102
x =102-73
x =29
Bài :Tìm x:
a)71-(33+x)=26
(33+x)=71-26
(33+x)=45
x =45-33
x =12
b)(x+73)-26=76
x+73 =76+26
x+73 =102
x =102-73
x =29
k cho mk nha
\(x.7+x.67\frac{4}{8}+x.2=98+76\)
\(x.\left(7+67\frac{4}{8}+2\right)=174\)
\(x.76,5=174\)
\(x\) \(=174:76,5\)
Sai bét rùi bạn ạ