Question

a•b=925
(a+12)•b=1225
__________
a,b=?

Answer 1

Răspuns:

$a \times b = 925 \\ a = \frac{925}{b} \\ (a + 12) \times b = 1225 \\ ( \frac{925}{b} + 12) \times b = 1225 \\ ( \frac{925}{b} + \frac{12b}{b} ) \times b = 1225 \\ ( \frac{925 + 12b}{b} ) \times b = 1225 \\ \frac{(925 + 12b) \times b}{b} = 1225 \\ 925 + 12b = 1225 \\ 12b = 1225 - 925 \\ 12b = 300 \\ b = \frac{300}{12} = 25 \\ a = \frac{925}{b} = \frac{925}{25} = 37$

Verificare :a•b =925

37•25 =925

925=925 adevărat

(a+12)•b =1225

(37+12)•25=1225

49•25 =1225

1225=1225 adevărat