Question

solve the equation 2x^3-15x^2+46x-42=0 given one root is 3 +√-5
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Answer 1

Step-by-step explanation:

STEP

1

:

49

Simplify ——

3

Equation at the end of step

1

:

14 49

((((x2)-5x)-(——•(x2)))-47)-(((((x2)+14x)+(——•x2))+27x)+42) = 0

3 3

STEP

2

:

Equation at the end of step 2

14 49x2

((((x2)-5x)-(——•(x2)))-47)-(((((x2)+14x)+————)+27x)+42) = 0

3 3

x2 + 14x (x2 + 14x) • 3

x2 + 14x = ———————— = ——————————————

1 3

Pull out like factors :

x2 + 14x = x • (x + 14)

Adding up the two equivalent fractions

x • (x+14) • 3 + 49x2 52x2 + 42x

————————————————————— = ——————————

3 3

14 (52x2+42x)

((((x2)-5x)-(——•(x2)))-47)-((——————————+27x)+42) = 0

3 3

Adding a whole to a fraction

27x 27x • 3

42 42 • 3

42 = —— = ——————

1 3