Question
Solve the inequality
Solve the inequality by testing the values in the interval
Solve the inequality by separating into cases
Solve for x
−5<x<−23
Alternative Form
x∈(−5,−23)
Evaluate
−2x2−13x−15>0
Rewrite the expression
−2x2−13x−15=0
Factor the expression
More Steps

Evaluate
−2x2−13x−15
Factor out −1 from the expression
−(2x2+13x+15)
Factor the expression
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Evaluate
2x2+13x+15
Rewrite the expression
2x2+(3+10)x+15
Calculate
2x2+3x+10x+15
Rewrite the expression
x×2x+x×3+5×2x+5×3
Factor out x from the expression
x(2x+3)+5×2x+5×3
Factor out 5 from the expression
x(2x+3)+5(2x+3)
Factor out 2x+3 from the expression
(x+5)(2x+3)
−(x+5)(2x+3)
−(x+5)(2x+3)=0
Divide the terms
(x+5)(2x+3)=0
When the product of factors equals 0,at least one factor is 0
x+5=02x+3=0
Solve the equation for x
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Evaluate
x+5=0
Move the constant to the right-hand side and change its sign
x=0−5
Removing 0 doesn't change the value,so remove it from the expression
x=−5
x=−52x+3=0
Solve the equation for x
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Evaluate
2x+3=0
Move the constant to the right-hand side and change its sign
2x=0−3
Removing 0 doesn't change the value,so remove it from the expression
2x=−3
Divide both sides
22x=2−3
Divide the numbers
x=2−3
Use b−a=−ba=−ba to rewrite the fraction
x=−23
x=−5x=−23
Determine the test intervals using the critical values
x<−5−5<x<−23x>−23
Choose a value form each interval
x1=−6x2=−3x3=−1
To determine if x<−5 is the solution to the inequality,test if the chosen value x=−6 satisfies the initial inequality
More Steps

Evaluate
−2(−6)2−13(−6)−15>0
Simplify
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Evaluate
−2(−6)2−13(−6)−15
Multiply the terms
−72−13(−6)−15
Multiply the numbers
−72+78−15
Calculate the sum or difference
−9
−9>0
Check the inequality
false
x<−5 is not a solutionx2=−3x3=−1
To determine if −5<x<−23 is the solution to the inequality,test if the chosen value x=−3 satisfies the initial inequality
More Steps

Evaluate
−2(−3)2−13(−3)−15>0
Simplify
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Evaluate
−2(−3)2−13(−3)−15
Multiply the terms
−18−13(−3)−15
Multiply the numbers
−18+39−15
Calculate the sum or difference
6
6>0
Check the inequality
true
x<−5 is not a solution−5<x<−23 is the solutionx3=−1
To determine if x>−23 is the solution to the inequality,test if the chosen value x=−1 satisfies the initial inequality
More Steps

Evaluate
−2(−1)2−13(−1)−15>0
Simplify
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Evaluate
−2(−1)2−13(−1)−15
Evaluate the power
−2×1−13(−1)−15
Any expression multiplied by 1 remains the same
−2−13(−1)−15
Simplify
−2+13−15
Calculate the sum or difference
−4
−4>0
Check the inequality
false
x<−5 is not a solution−5<x<−23 is the solutionx>−23 is not a solution
Solution
−5<x<−23
Alternative Form
x∈(−5,−23)
Show Solution
