Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
x1=728−77,x2=728+77
Alternative Form
x1≈2.746434,x2≈5.253566
Evaluate
7(x−4)2=11
Expand the expression
More Steps

Evaluate
7(x−4)2
Expand the expression
More Steps

Evaluate
(x−4)2
Use (a−b)2=a2−2ab+b2 to expand the expression
x2−2x×4+42
Calculate
x2−8x+16
7(x2−8x+16)
Apply the distributive property
7x2−7×8x+7×16
Multiply the numbers
7x2−56x+7×16
Multiply the numbers
7x2−56x+112
7x2−56x+112=11
Move the expression to the left side
7x2−56x+101=0
Substitute a=7,b=−56 and c=101 into the quadratic formula x=2a−b±b2−4ac
x=2×756±(−56)2−4×7×101
Simplify the expression
x=1456±(−56)2−4×7×101
Simplify the expression
More Steps

Evaluate
(−56)2−4×7×101
Multiply the terms
More Steps

Multiply the terms
4×7×101
Multiply the terms
28×101
Multiply the numbers
2828
(−56)2−2828
Rewrite the expression
562−2828
Evaluate the power
3136−2828
Subtract the numbers
308
x=1456±308
Simplify the radical expression
More Steps

Evaluate
308
Write the expression as a product where the root of one of the factors can be evaluated
4×77
Write the number in exponential form with the base of 2
22×77
The root of a product is equal to the product of the roots of each factor
22×77
Reduce the index of the radical and exponent with 2
277
x=1456±277
Separate the equation into 2 possible cases
x=1456+277x=1456−277
Simplify the expression
More Steps

Evaluate
x=1456+277
Divide the terms
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Evaluate
1456+277
Rewrite the expression
142(28+77)
Cancel out the common factor 2
728+77
x=728+77
x=728+77x=1456−277
Simplify the expression
More Steps

Evaluate
x=1456−277
Divide the terms
More Steps

Evaluate
1456−277
Rewrite the expression
142(28−77)
Cancel out the common factor 2
728−77
x=728−77
x=728+77x=728−77
Solution
x1=728−77,x2=728+77
Alternative Form
x1≈2.746434,x2≈5.253566
Show Solution
