Question 390325
The product of three integers is 90. 
xyz = 90
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The second number is twice the first number.
y = 2x
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The third number is two more than the first number. What are the three numbers?
z = x+2
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Equation:
Substitute for y and for z and solve for "x":
x(2x)(x+2) = 90
2x^3+4x^2-90 = 0
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x^3 + 2x^2 - 45 = 0 
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I graphed the cubic and found a solution at x = 3
Then y = 2x = 6
And z = x+2 = 5
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Check:
3*6*5 = 90 
90 = 90
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Cheers,
Stan H.