Question
Solve the equation
x1=21+13,x2=23+21
Alternative Form
x1≈2.302776,x2≈3.791288
Evaluate
x2−2x−3=x
Rewrite the expression
x2−2x−3−x=0
Separate the equation into 2 possible cases
x2−2x−3−x=0,x2−2x−3≥0−(x2−2x−3)−x=0,x2−2x−3<0
Solve the equation
More Steps

Evaluate
x2−2x−3−x=0
Calculate
More Steps

Evaluate
−2x−x
Collect like terms by calculating the sum or difference of their coefficients
(−2−1)x
Subtract the numbers
−3x
x2−3x−3=0
Substitute a=1,b=−3 and c=−3 into the quadratic formula x=2a−b±b2−4ac
x=23±(−3)2−4(−3)
Simplify the expression
More Steps

Evaluate
(−3)2−4(−3)
Multiply the numbers
(−3)2−(−12)
Rewrite the expression
32−(−12)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
32+12
Evaluate the power
9+12
Add the numbers
21
x=23±21
Separate the equation into 2 possible cases
x=23+21x=23−21
x=23+21x=23−21,x2−2x−3≥0−(x2−2x−3)−x=0,x2−2x−3<0
Solve the inequality
More Steps

Evaluate
x2−2x−3≥0
Move the constant to the right side
x2−2x≥0−(−3)
Add the terms
x2−2x≥3
Add the same value to both sides
x2−2x+1≥3+1
Evaluate
x2−2x+1≥4
Evaluate
(x−1)2≥4
Take the 2-th root on both sides of the inequality
(x−1)2≥4
Calculate
∣x−1∣≥2
Separate the inequality into 2 possible cases
x−1≥2x−1≤−2
Calculate
More Steps

Evaluate
x−1≥2
Move the constant to the right side
x≥2+1
Add the numbers
x≥3
x≥3x−1≤−2
Calculate
More Steps

Evaluate
x−1≤−2
Move the constant to the right side
x≤−2+1
Add the numbers
x≤−1
x≥3x≤−1
Find the union
x∈(−∞,−1]∪[3,+∞)
x=23+21x=23−21,x∈(−∞,−1]∪[3,+∞)−(x2−2x−3)−x=0,x2−2x−3<0
Solve the equation
More Steps

Evaluate
−(x2−2x−3)−x=0
Calculate
−x2+2x+3−x=0
Calculate
More Steps

Evaluate
2x−x
Collect like terms by calculating the sum or difference of their coefficients
(2−1)x
Subtract the numbers
x
−x2+x+3=0
Multiply both sides
x2−x−3=0
Substitute a=1,b=−1 and c=−3 into the quadratic formula x=2a−b±b2−4ac
x=21±(−1)2−4(−3)
Simplify the expression
More Steps

Evaluate
(−1)2−4(−3)
Evaluate the power
1−4(−3)
Multiply the numbers
1−(−12)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
1+12
Add the numbers
13
x=21±13
Separate the equation into 2 possible cases
x=21+13x=21−13
x=23+21x=23−21,x∈(−∞,−1]∪[3,+∞)x=21+13x=21−13,x2−2x−3<0
Solve the inequality
More Steps

Evaluate
x2−2x−3<0
Move the constant to the right side
x2−2x<0−(−3)
Add the terms
x2−2x<3
Add the same value to both sides
x2−2x+1<3+1
Evaluate
x2−2x+1<4
Evaluate
(x−1)2<4
Take the 2-th root on both sides of the inequality
(x−1)2<4
Calculate
∣x−1∣<2
Separate the inequality into 2 possible cases
{x−1<2x−1>−2
Calculate
More Steps

Evaluate
x−1<2
Move the constant to the right side
x<2+1
Add the numbers
x<3
{x<3x−1>−2
Calculate
More Steps

Evaluate
x−1>−2
Move the constant to the right side
x>−2+1
Add the numbers
x>−1
{x<3x>−1
Find the intersection
−1<x<3
x=23+21x=23−21,x∈(−∞,−1]∪[3,+∞)x=21+13x=21−13,−1<x<3
Find the intersection
x=23+21x=21+13x=21−13,−1<x<3
Find the intersection
x=23+21x=21+13
Solution
x1=21+13,x2=23+21
Alternative Form
x1≈2.302776,x2≈3.791288
Show Solution
