a) x + 2,57 = 14,25 - 6,3
=> x + 2,57 = 7,95
=> x = 7,95 - 2,57
=> x = 5,38
Vậy x = 5,38
b) 12,9 - x = 4,2 + 2,4
=> 12,9 - x = 6,6
=> x = 12,9 - 6,6
=> x = 6,3
Vậy x = 6,3
c) x . 93 + x . 0,7 = 100
=> x . (93 + 0,7) = 100
=> x . 93,7 = 100
=> x = 100 : 93,7
=> x = 1000/937
Vậy x = 1000/937
a) \(x+2,57=14,25-6,3\)
\(x+2,57=7,95\)
\(x=7,95-2,57\)
\(\Rightarrow x=5,38\)
b) \(12,9-x=4,2+2,4\)
\(12,9-x=6,6\)
\(x=12,9-6,6\)
\(\Rightarrow x=6,3\)
c) \(x.93+x.0,7=100\)
\(x\left(93+0,7\right)=100\)
\(x.93,7=100\)
\(x=100:93,7\)
\(\Rightarrow x=\frac{1000}{937}\)
d) \(\frac{x}{5}=\frac{4}{2}\)
Ta có: \(x.2=4.5\)
\(x.2=20\)
\(x=20:2\)
\(\Rightarrow x=10\)