Question

Suma dintre 1 supra 3 din el si sfertul lui este egala cu 0,(21)

Answer 1

$x - nr.$

$\frac{1}{3} \times x + \frac{x}{4} = 0.(21)$

$\frac{x}{3} + \frac{x}{4} = \frac{21}{99}$

$\frac{x}{3} + \frac{x}{4} = \frac{7}{33}$

$\frac{4x}{12} + \frac{3x}{12} = \frac{7}{33}$

$\frac{4x + 3x}{12} = \frac{7}{33}$

$\frac{7x}{12} = \frac{7}{33}$

$33 \times 7x = 12 \times 7 \: | \div 7$

$33x = 12$

$x = \frac{12}{33}$

$x = 0.(36)$