What method would you choose to solve the equation 2x2-7=9 ? Explain why you chose this method.
Accepted Solution
I would add 7 to get ...... 2x² = 16then divide by 2 to get... x² = 8Now, I would take the square root, recognizing that both positive and negative values will solve the problem.... x = ±√8The root can be simplified, so we have ...... x = ±2√2_____The above method seemed the most obvious method to me. One could use the quadratic formula, but that seems to involve more operations.... 2x² -16 = 0 . . . . subtract 9... x = (-0 ± √(0² -4·2·(-16)))/(2·2) . . . . put the coefficients into the formula... x = ±(√128)/4 = ±√8 = ±2√2 . . . . . simplify the result
