Use any method to solve the equation. If necessary, round to the nearest hundredth.
9x^2- 21 = 0
what a lot of work, just to get a wrong answer!
9x^2- 21 = 0
3x^2 - 7 = 0
3x^2 = 7
x^2 = 7/3
x = ±√(7/3) ≈ ±1.528
Apologies for the mistake. You are correct. The correct solution to the equation 9x^2 - 21 = 0 is x ≈ ±1.528.
To solve the equation 9x^2- 21 = 0, we can use the quadratic formula. The quadratic formula states that for an equation in the form ax^2 + bx + c = 0, the solutions are given by:
x = (-b ± √(b^2 - 4ac)) / (2a)
In this case, a = 9, b = 0, and c = -21, so we have:
x = (-0 ± √(0^2 - 4(9)(-21))) / (2(9))
Simplifying further:
x = ± √(0 + 756) / 18
x = ± √756 / 18
Using a calculator or estimation, we find:
x ≈ ± 4.60 / 18
x ≈ ± 0.26
Therefore, the solutions to the equation are approximately x = 0.26 and x = -0.26.