Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=25−23,x2=25+23
Alternative Form
x1≈0.767949,x2≈4.232051
Evaluate
4x2−20x=−13
Move the expression to the left side
4x2−20x+13=0
Substitute a=4,b=−20 and c=13 into the quadratic formula x=2a−b±b2−4ac
x=2×420±(−20)2−4×4×13
Simplify the expression
x=820±(−20)2−4×4×13
Simplify the expression
More Steps

Evaluate
(−20)2−4×4×13
Multiply the terms
More Steps

Multiply the terms
4×4×13
Multiply the terms
16×13
Multiply the numbers
208
(−20)2−208
Rewrite the expression
202−208
Evaluate the power
400−208
Subtract the numbers
192
x=820±192
Simplify the radical expression
More Steps

Evaluate
192
Write the expression as a product where the root of one of the factors can be evaluated
64×3
Write the number in exponential form with the base of 8
82×3
The root of a product is equal to the product of the roots of each factor
82×3
Reduce the index of the radical and exponent with 2
83
x=820±83
Separate the equation into 2 possible cases
x=820+83x=820−83
Simplify the expression
More Steps

Evaluate
x=820+83
Divide the terms
More Steps

Evaluate
820+83
Rewrite the expression
84(5+23)
Cancel out the common factor 4
25+23
x=25+23
x=25+23x=820−83
Simplify the expression
More Steps

Evaluate
x=820−83
Divide the terms
More Steps

Evaluate
820−83
Rewrite the expression
84(5−23)
Cancel out the common factor 4
25−23
x=25−23
x=25+23x=25−23
Solution
x1=25−23,x2=25+23
Alternative Form
x1≈0.767949,x2≈4.232051
Show Solution
