bạn nào bít giúp mìn với dang can gap lam lam lam ai giup duoc thi thank nhiu
a) x/49 = -3/7
x/49=-21/7
=>x=-21
b)x-2/12=2/3
x-2/12=8/12
=>x-2=8
x=8+2
x=10
\(\dfrac{x}{49}=\dfrac{-3}{7}\)
ta có \(x\cdot7=49\cdot-3\)
hay \(x.7=-147\)
hay\(x=-147:7\)\(\Rightarrow x=-21\)
b) \(x-\dfrac{2}{12}=\dfrac{2}{3}\)
\(x=\dfrac{2}{3}+\dfrac{2}{12}\)
\(x=\dfrac{5}{6}\)
c) \(x-\dfrac{1}{9}=15-3\)
\(x-\dfrac{1}{9}=12\)
\(x=12+\dfrac{1}{9}\)
\(x=\dfrac{109}{9}\)
d)\(\dfrac{3}{x}=\dfrac{9}{35}=\dfrac{-3}{7}\)
ta có: \(x\cdot9\cdot84=3\cdot35\cdot-3\)
\(x\cdot9\cdot84=-3780\)
\(x=-3780:\left(9\cdot7\right)\)
\(x=60\)
