Problem3x2−12=03x^2 - 12 = 03x2−12=0分步解答两边同加 121212:3x2=123x^2 = 123x2=12。两边同除以 333:x2=4x^2 = 4x2=4。取正负平方根:x=±2x = \pm 2x=±2。答案x=2orx=−2x = 2 \quad \text{or} \quad x = -2x=2orx=−2想解其他题?打开 quadratic 求解器 →相关例题/solve/algebra/x2-minus-9/solve/algebra/x2-minus-25