Tìm số tự nhiên x: a) 75-x = 20; b) 5 (x - 25) = 2.5 + 5
Giải thích
a) \(75 - x = 20\)
\(x = 75 - 20\)
\(x = 55\)
b) \(5.\left( {x - 25} \right) = 2.5 + 5\)
\(5\left( {x - 25} \right) = 15\)
\(x - 25 = 15:5\)
\(x - 25 = 3\)
\(x = 3 + 25\)
\(x = 28\)
a) \(75 - x = 20\)
\(x = 75 - 20\)
\(x = 55\)
b) \(5.\left( {x - 25} \right) = 2.5 + 5\)
\(5\left( {x - 25} \right) = 15\)
\(x - 25 = 15:5\)
\(x - 25 = 3\)
\(x = 3 + 25\)
\(x = 28\)