Find the exact solution of x.

Question

3x^2 + 7 = 28

±√7
7
-7
±7

Answer 1

To solve the equation \( 3x^2 + 7 = 28 \), we first isolate \( x^2 \).

1. Subtract 7 from both sides: \[ 3x^2 = 28 - 7 \] \[ 3x^2 = 21 \]

2. Now, divide both sides by 3: \[ x^2 = \frac{21}{3} = 7 \]

3. Finally, take the square root of both sides: \[ x = \pm \sqrt{7} \]

The exact solution is \( x = \pm \sqrt{7} \).

So, the answer is \( \pm \sqrt{7} \).