Question
Solve the inequality
Solve the inequality by testing the values in the interval
Solve for x
−2<x<2
Alternative Form
x∈(−2,2)
Evaluate
4x2−7<x2−1
Move the expression to the left side
4x2−7−(x2−1)<0
Subtract the terms
More Steps

Evaluate
4x2−7−(x2−1)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
4x2−7−x2+1
Subtract the terms
More Steps

Evaluate
4x2−x2
Collect like terms by calculating the sum or difference of their coefficients
(4−1)x2
Subtract the numbers
3x2
3x2−7+1
Add the numbers
3x2−6
3x2−6<0
Rewrite the expression
3x2−6=0
Move the constant to the right-hand side and change its sign
3x2=0+6
Removing 0 doesn't change the value,so remove it from the expression
3x2=6
Divide both sides
33x2=36
Divide the numbers
x2=36
Divide the numbers
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Evaluate
36
Reduce the numbers
12
Calculate
2
x2=2
Take the root of both sides of the equation and remember to use both positive and negative roots
x=±2
Separate the equation into 2 possible cases
x=2x=−2
Determine the test intervals using the critical values
x<−2−2<x<2x>2
Choose a value form each interval
x1=−2x2=0x3=2
To determine if x<−2 is the solution to the inequality,test if the chosen value x=−2 satisfies the initial inequality
More Steps

Evaluate
4(−2)2−7<(−2)2−1
Simplify
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Evaluate
4(−2)2−7
Multiply the terms
16−7
Subtract the numbers
9
9<(−2)2−1
Subtract the numbers
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Evaluate
(−2)2−1
Simplify
22−1
Evaluate the power
4−1
Subtract the numbers
3
9<3
Check the inequality
false
x<−2 is not a solutionx2=0x3=2
To determine if −2<x<2 is the solution to the inequality,test if the chosen value x=0 satisfies the initial inequality
More Steps

Evaluate
4×02−7<02−1
Simplify
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Evaluate
4×02−7
Calculate
4×0−7
Any expression multiplied by 0 equals 0
0−7
Removing 0 doesn't change the value,so remove it from the expression
−7
−7<02−1
Simplify
More Steps

Evaluate
02−1
Calculate
0−1
Removing 0 doesn't change the value,so remove it from the expression
−1
−7<−1
Check the inequality
true
x<−2 is not a solution−2<x<2 is the solutionx3=2
To determine if x>2 is the solution to the inequality,test if the chosen value x=2 satisfies the initial inequality
More Steps

Evaluate
4×22−7<22−1
Simplify
More Steps

Evaluate
4×22−7
Multiply the terms
24−7
Evaluate the power
16−7
Subtract the numbers
9
9<22−1
Subtract the numbers
More Steps

Evaluate
22−1
Evaluate the power
4−1
Subtract the numbers
3
9<3
Check the inequality
false
x<−2 is not a solution−2<x<2 is the solutionx>2 is not a solution
Solution
−2<x<2
Alternative Form
x∈(−2,2)
Show Solution
