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Lyzandralo
a fost răspuns

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


Răspuns :

[tex]a) \frac{40}{100} \times a = 18000[/tex]

[tex] \frac{4}{10} \times a = 18000[/tex]

[tex] \frac{2}{5} \times a = 18000[/tex]

[tex] \frac{2a}{5} = 18000[/tex]

[tex]2a = 5 \times 18000[/tex]

[tex]2a = 90000[/tex]

[tex]a = \frac{90000}{2} [/tex]

[tex]a = 45000[/tex]

[tex]b) \frac{40}{100} \times x = 12[/tex]

[tex] \frac{4}{10} \times x = 12[/tex]

[tex] \frac{4x}{10} = 12[/tex]

[tex] \frac{2x}{5} = 12[/tex]

[tex]2x = 5 \times 12[/tex]

[tex]2x = 60[/tex]

[tex]x = \frac{60}{2} [/tex]

[tex]x = 30[/tex]

[tex]c) \frac{12}{100} \times x = 30[/tex]

[tex] \frac{6}{50} \times x = 30[/tex]

[tex] \frac{3}{25} \times x = 30[/tex]

[tex] \frac{3x}{25} = 30[/tex]

[tex]3x = 25 \times 30[/tex]

[tex]3x = 750[/tex]

[tex]x = \frac{750}{3} [/tex]

[tex]x = 250[/tex]