Question

Daca a+b=7 si a*b=10,atunci expresia a^2+b^2 este egala cu ...

Answer 1

Daca ridici la patrat a+b=7  obtii $a^{2} +2a*b+ b^{2} =49$. Stii ca a*b=10 deci 2a*b=20. Obtii $a^{2} +20+ b^{2} =49$, de unde $a^{2} +b^{2}=29$.

Answer 2

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