Question

Afla numerele necunoscute
a) 40% din a este egal cu 18000
b) 40% ∙ x = 12
c) 12% ∙ x = 30

Answer 1

$a) \frac{40}{100} \times a = 18000$

$\frac{4}{10} \times a = 18000$

$\frac{2}{5} \times a = 18000$

$\frac{2a}{5} = 18000$

$2a = 5 \times 18000$

$2a = 90000$

$a = \frac{90000}{2}$

$a = 45000$

$b) \frac{40}{100} \times x = 12$

$\frac{4}{10} \times x = 12$

$\frac{4x}{10} = 12$

$\frac{2x}{5} = 12$

$2x = 5 \times 12$

$2x = 60$

$x = \frac{60}{2}$

$x = 30$

$c) \frac{12}{100} \times x = 30$

$\frac{6}{50} \times x = 30$

$\frac{3}{25} \times x = 30$

$\frac{3x}{25} = 30$

$3x = 25 \times 30$

$3x = 750$

$x = \frac{750}{3}$

$x = 250$