Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=1030−645,x2=1030+645
Alternative Form
x1≈0.460315,x2≈5.539685
Evaluate
5(x−3)2×4=129
Multiply the terms
20(x−3)2=129
Expand the expression
More Steps

Evaluate
20(x−3)2
Expand the expression
More Steps

Evaluate
(x−3)2
Use (a−b)2=a2−2ab+b2 to expand the expression
x2−2x×3+32
Calculate
x2−6x+9
20(x2−6x+9)
Apply the distributive property
20x2−20×6x+20×9
Multiply the numbers
20x2−120x+20×9
Multiply the numbers
20x2−120x+180
20x2−120x+180=129
Move the expression to the left side
20x2−120x+51=0
Substitute a=20,b=−120 and c=51 into the quadratic formula x=2a−b±b2−4ac
x=2×20120±(−120)2−4×20×51
Simplify the expression
x=40120±(−120)2−4×20×51
Simplify the expression
More Steps

Evaluate
(−120)2−4×20×51
Multiply the terms
More Steps

Multiply the terms
4×20×51
Multiply the terms
80×51
Multiply the numbers
4080
(−120)2−4080
Rewrite the expression
1202−4080
Evaluate the power
14400−4080
Subtract the numbers
10320
x=40120±10320
Simplify the radical expression
More Steps

Evaluate
10320
Write the expression as a product where the root of one of the factors can be evaluated
16×645
Write the number in exponential form with the base of 4
42×645
The root of a product is equal to the product of the roots of each factor
42×645
Reduce the index of the radical and exponent with 2
4645
x=40120±4645
Separate the equation into 2 possible cases
x=40120+4645x=40120−4645
Simplify the expression
More Steps

Evaluate
x=40120+4645
Divide the terms
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Evaluate
40120+4645
Rewrite the expression
404(30+645)
Cancel out the common factor 4
1030+645
x=1030+645
x=1030+645x=40120−4645
Simplify the expression
More Steps

Evaluate
x=40120−4645
Divide the terms
More Steps

Evaluate
40120−4645
Rewrite the expression
404(30−645)
Cancel out the common factor 4
1030−645
x=1030−645
x=1030+645x=1030−645
Solution
x1=1030−645,x2=1030+645
Alternative Form
x1≈0.460315,x2≈5.539685
Show Solution
