Tìm x biết: 5x(x - 3) = 5x^2 + 7x - 5
Tìm x biết: 5x(x – 3) = 5x2 + 7x – 5.
5x(x – 3) = 5x2 + 7x – 5
⇔ 5x2 – 15x – 5x2 – 7x + 5 = 0
⇔ –22x = –5
⇔ \(x = \frac{{ - 5}}{{ - 22}} = \frac{5}{{22}}\)
Vậy \(x = \frac{5}{{22}}\).