Question

Rezolvati in R ecuatia:$4 x^{2} -7=9$

Answer 1

4x²-7=9

4x²=9+7

4x²=16 |:4

x²=4 

√x²= √4

|x|=2  => x={-2;2}

Answer 2

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