in this case it is to find the roots of the polynomial. We have then: x ^ 2-4x-9 = 29 Rewriting: x ^ 2-4x-38 = 0 Applying resolver we have x = (- b +/- root (b ^ 2 - 4ac)) / (2a) Substituting values: x = (- (- 4) +/- root ((- 4) ^ 2 - 4 (1) (- 38))) / (2 (1)) x = (4 +/- root (16 + 152))) / (2) x = (2 +/- root (42)) Answer: x = (2 +/- root (42)) (option1)
x²-4x-9=29 You need to complete the square by following the next few steps. First, you need to place the x²-4x into squared brackets, by dividing the coefficient of x by 2x and dividing x² by x: (x-2)² Find out what this equals to: x²-4x+4 We can start off here, as we have obtained the x²-4x. However, we need to get from +4 to -9. To do this, we must minus 13. Therefore, our equation now looks like this: (x-2)²-13=29 Now, just solve as you normally would, to isolate x: (x-2)²-13=29 Add 13 on both sides (x-2)²=42 Square root both sides x-2=±√42 Add 2 on both sides x=2±√42 So, your answer is the first option
