Question

problema cinci va rog!!!​

Answer 1

Răspuns:

Explicație pas cu pas:

Notez varsta tata cu ,, t" si varsta fiu = ,,f"

t = 5 × f

t + 21 = 2 × ( f + 21 )  ⇒   t = 2 × f + 42 - 21 ⇒   t = 2 × f + 21

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5 × f = 2 × f + 21

5 × f - 2 × f = 21

3 × f = 21

f = 21 : 3

f = 7 ani → varsta fiu

5 × 7 = 35 ani are tata

Verific:    35 + 21 = 2 x ( 7 + 21)

                        56 = 2 x 28√

Answer 2

T = 5 × F

T + 21 = 2 × ( F + 21 )

T = 2 × F + 21

5 × F = 2 × F + 21

5 × F - 2 × F = 21

3 × F = 21

F = 21 : 3

F = 7

T = 5 × 7

T = 35