please help me with this question for which real values of b do the equations x^3 + bx^2 + 2bx -1 =0 and x^2 + (b-1)x + b = 0 have a common root thank you
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Let be the common root. We observe that . Multiplying (2) by and then substracting from (1), we have (3) The equality (2) can be written as Using (3) we have . Plug in (2) and we have . If , the common root is . If , the common root is .
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