👤

Rezolvati in R ecuatia:[tex]4 x^{2} -7=9[/tex]

Răspuns :

4x²-7=9

4x²=9+7

4x²=16 |:4

x²=4 

√x²= √4

|x|=2  => x={-2;2}
4x²-7=9/+7
4x²=16/:4
x²=4
x=√4
=> x∈{2,-2}