Question
Solve the inequality
Solve the inequality by testing the values in the interval
Solve the inequality by separating into cases
Solve for x
−23<x<4
Alternative Form
x∈(−23,4)
Evaluate
2x2−5x−1<11
Move the expression to the left side
2x2−5x−1−11<0
Subtract the numbers
2x2−5x−12<0
Rewrite the expression
2x2−5x−12=0
Factor the expression
More Steps

Evaluate
2x2−5x−12
Rewrite the expression
2x2+(3−8)x−12
Calculate
2x2+3x−8x−12
Rewrite the expression
x×2x+x×3−4×2x−4×3
Factor out x from the expression
x(2x+3)−4×2x−4×3
Factor out −4 from the expression
x(2x+3)−4(2x+3)
Factor out 2x+3 from the expression
(x−4)(2x+3)
(x−4)(2x+3)=0
When the product of factors equals 0,at least one factor is 0
x−4=02x+3=0
Solve the equation for x
More Steps

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=42x+3=0
Solve the equation for x
More Steps

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=4x=−23
Determine the test intervals using the critical values
x<−23−23<x<4x>4
Choose a value form each interval
x1=−3x2=1x3=5
To determine if x<−23 is the solution to the inequality,test if the chosen value x=−3 satisfies the initial inequality
More Steps

Evaluate
2(−3)2−5(−3)−1<11
Simplify
More Steps

Evaluate
2(−3)2−5(−3)−1
Multiply the terms
18−5(−3)−1
Multiply the numbers
18+15−1
Calculate the sum or difference
32
32<11
Check the inequality
false
x<−23 is not a solutionx2=1x3=5
To determine if −23<x<4 is the solution to the inequality,test if the chosen value x=1 satisfies the initial inequality
More Steps

Evaluate
2×12−5×1−1<11
Simplify
More Steps

Evaluate
2×12−5×1−1
1 raised to any power equals to 1
2×1−5×1−1
Any expression multiplied by 1 remains the same
2−5×1−1
Any expression multiplied by 1 remains the same
2−5−1
Subtract the numbers
−4
−4<11
Check the inequality
true
x<−23 is not a solution−23<x<4 is the solutionx3=5
To determine if x>4 is the solution to the inequality,test if the chosen value x=5 satisfies the initial inequality
More Steps

Evaluate
2×52−5×5−1<11
Simplify
More Steps

Evaluate
2×52−5×5−1
Multiply the terms
50−5×5−1
Multiply the numbers
50−25−1
Subtract the numbers
24
24<11
Check the inequality
false
x<−23 is not a solution−23<x<4 is the solutionx>4 is not a solution
Solution
−23<x<4
Alternative Form
x∈(−23,4)
Show Solution
