a, 2015 - 2 × X = 101
2 x X = 2015 - 101
2 x X = 1914
X = 1914 : 2
X = 957
1a. 2015 - 2 x X = 101
2 x X = 2015 - 101
X = 1914 : 2
X = 957
b. 7 - (11 + X - 13) : \(2\frac{2}{3}\)= 2
(11 + X - 13) : \(2\frac{2}{3}\) = 7 - 2
11 + X - 13 = 5 x \(2\frac{2}{3}\)
11 + X = \(\frac{40}{3}\)+ 13
X = \(\frac{79}{3}\)- 11
X = \(\frac{46}{3}\)
c. 2012 - 5 x X = 17
5 x X = 2012 - 17
X = 1995 : 5
X = 399
d. \(5\frac{3}{4}\)+ (X - 2) x \(\frac{1}{3}\)= \(17\frac{3}{4}\)
(X - 2) x \(\frac{1}{3}\) = \(17\frac{3}{4}\)- \(5\frac{3}{4}\)
X - 2 = 12 : \(\frac{1}{3}\)
X = 36 + 2
X = 38
e. 12 x (X - 5) + 73 = 20
12 x (X - 5) = 20 - 73
X - 5 = -53 : 12
X = \(\frac{-53}{12}\)+ 5
X = \(\frac{7}{12}\)
a )
2015 - 2 x X = 101
2 x X = 2015 - 101
2 x X = 1914
X = 1914 : 2
X = 957
b )
7 - ( 11 + X - 13 ) : \(2\frac{2}{3}\) = 2
( 11 + X - 13 ) : \(2\frac{2}{3}\) = 7 - 2
( 11 + X - 13 ) : \(2\frac{2}{3}\) = 5
11 + X - 13 = 5 x \(2\frac{2}{3}\)
11 + X - 13 = \(13\frac{1}{3}\)
X = \(13\frac{1}{3}\) + 13 - 11
X = \(15\frac{1}{3}\)
c )
2012 - 5 x X = 17
5 x X = 2012 - 17
5 x X = 1995
X = 1995 : 5
X = 399
d )
\(5\frac{3}{4}\) + ( X - 2 ) x \(\frac{1}{3}\) = \(17\frac{3}{4}\)
( X - 2 ) x \(\frac{1}{3}\) = \(17\frac{3}{4}+5\frac{3}{4}\)
( X - 2 ) x \(\frac{1}{3}\) = \(23\frac{1}{2}\)
X - 2 = \(23\frac{1}{2}\div\frac{1}{3}\)
X - 2 = 47
X = 47 + 2
X = 49
e ) Mình không làm đực câu này đâu
Học tốt nhé bạn !