Question

1.Rezolvati in multimea numerelor reale ecuatiile: 3√2x-1=5
2.Rezolvati sistemele de doua ecuatii cu doua necunoscute, unde x,y apartine r: b)3√2x-y=7 2√2x+y=3

Answer 1

Răspuns:

Explicație pas cu pas:

1) 3√2x-1=5 <=>  3√2x = 1+ 5 <=>

3√2x = 6   I : 3 => √2x = 2  => x = 2/√2 = 2√2/2 = √2

x = √2

2)

3√2x-y=7     (1)

2√2x+y=3    (2)

__________________

metoda reducerii (1)+(2)

__________________

3√2x + 2√2x = 7+3 <=>

5√2x = 10  I:5  =>

√2x = 2 => x = 2/√2 = 2√2/2 = √2 => x = √2

2√2·√2 + y = 3  <=> 4 + y = 3 => y = 3-4 => y = -1