Question
Solve the equation
x=4
Evaluate
x3+x2−80=0
Factor the expression
(x−4)(x2+5x+20)=0
Separate the equation into 2 possible cases
x−4=0x2+5x+20=0
Solve the equation
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Evaluate
x−4=0
Move the constant to the right-hand side and change its sign
x=0+4
Removing 0 doesn't change the value,so remove it from the expression
x=4
x=4x2+5x+20=0
Solve the equation
More Steps

Evaluate
x2+5x+20=0
Substitute a=1,b=5 and c=20 into the quadratic formula x=2a−b±b2−4ac
x=2−5±52−4×20
Simplify the expression
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Evaluate
52−4×20
Multiply the numbers
52−80
Evaluate the power
25−80
Subtract the numbers
−55
x=2−5±−55
The expression is undefined in the set of real numbers
x∈/R
x=4x∈/R
Solution
x=4
Show Solution
