Question :
x+12/x<7
Solve the inequality
Solve the inequality by testing the values in the interval
Solve the inequality by separating into cases
x∈(−∞,0)∪(3,4)
Evaluate
x+x12<7
Find the domain
x+x12<7,x=0
Move the expression to the left side
x+x12−7<0
Calculate the sum or difference
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Evaluate
x+x12−7
Reduce fractions to a common denominator
xx×x+x12−x7x
Write all numerators above the common denominator
xx×x+12−7x
Multiply the terms
xx2+12−7x
xx2+12−7x<0
Set the numerator and denominator of xx2+12−7x equal to 0 to find the values of x where sign changes may occur
x2+12−7x=0x=0
Calculate
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Evaluate
x2+12−7x=0
Factor the expression
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Evaluate
x2+12−7x
Reorder the terms
x2−7x+12
Rewrite the expression
x2+(−3−4)x+12
Calculate
x2−3x−4x+12
Rewrite the expression
x×x−x×3−4x+4×3
Factor out x from the expression
x(x−3)−4x+4×3
Factor out −4 from the expression
x(x−3)−4(x−3)
Factor out x−3 from the expression
(x−4)(x−3)
(x−4)(x−3)=0
When the product of factors equals 0,at least one factor is 0
x−4=0x−3=0
Solve the equation for x
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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=4x−3=0
Solve the equation for x
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Evaluate
x−3=0
Move the constant to the right-hand side and change its sign
x=0+3
Removing 0 doesn't change the value,so remove it from the expression
x=3
x=4x=3
x=4x=3x=0
Determine the test intervals using the critical values
x<00<x<33<x<4x>4
Choose a value form each interval
x1=−1x2=2x3=27x4=5
To determine if x<0 is the solution to the inequality,test if the chosen value x=−1 satisfies the initial inequality
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Evaluate
−1+−112<7
Simplify
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Evaluate
−1+−112
Divide the terms
−1−12
Subtract the numbers
−13
−13<7
Check the inequality
true
x<0 is the solutionx2=2x3=27x4=5
To determine if 0<x<3 is the solution to the inequality,test if the chosen value x=2 satisfies the initial inequality
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Evaluate
2+212<7
Simplify
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Evaluate
2+212
Divide the terms
2+6
Add the numbers
8
8<7
Check the inequality
false
x<0 is the solution0<x<3 is not a solutionx3=27x4=5
To determine if 3<x<4 is the solution to the inequality,test if the chosen value x=27 satisfies the initial inequality
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Evaluate
27+2712<7
Simplify
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Evaluate
27+2712
Divide the terms
27+724
Reduce fractions to a common denominator
2×77×7+7×224×2
Multiply the numbers
147×7+7×224×2
Multiply the numbers
147×7+1424×2
Write all numerators above the common denominator
147×7+24×2
Multiply the numbers
1449+24×2
Multiply the numbers
1449+48
Add the numbers
1497
1497<7
Calculate
6.92˙85714˙<7
Check the inequality
true
x<0 is the solution0<x<3 is not a solution3<x<4 is the solutionx4=5
To determine if x>4 is the solution to the inequality,test if the chosen value x=5 satisfies the initial inequality
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Evaluate
5+512<7
Add the numbers
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Evaluate
5+512
Reduce fractions to a common denominator
55×5+512
Write all numerators above the common denominator
55×5+12
Multiply the numbers
525+12
Add the numbers
537
537<7
Calculate
7.4<7
Check the inequality
false
x<0 is the solution0<x<3 is not a solution3<x<4 is the solutionx>4 is not a solution
The original inequality is a strict inequality,so does not include the critical value ,the final solution is x∈(−∞,0)∪(3,4)
x∈(−∞,0)∪(3,4)
Check if the solution is in the defined range
x∈(−∞,0)∪(3,4),x=0
Solution
x∈(−∞,0)∪(3,4)
Show Solution
