his is a quadratic equation . We order to equate to zero
2x² – 7 = 9
2x² - 7-9 = 0
2x² - 16 = 0
This equation is a binomial
2* (x² - 8) = 0
We choose the simplest method . The equation with practice it can be calculated in the memory
The product is equal to 0 if one of the factors is zero
2≠0 ∨ x² - 8 = 0
x² = √8
x = √8 ∨ x= - √8
Answer : x = √8 ∨ x = -√8
