Solve x^(2)-8x 16=25

Question

Solve the quadratic equation

Solve using the quadratic formula

Solve by completing the square

Solve using the PQ formula

x_{1} = 64 - 4121, x_{2} = 64 + 4121

Alternative Form

x_{1} \approx - 0.195015, x_{2} \approx 128.195015

Evaluate

x^{2} - 8 x \times 16 = 25

Multiply the terms

x^{2} - 128 x = 25

Move the expression to the left side

x^{2} - 128 x - 25 = 0

Substitute a= 1,b= - 128 and c= - 25 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{128 \pm ( - 128 ) ^{2} - 4 ( - 25 )}{2}

Simplify the expression

More Steps

x = \frac{128 \pm 16484}{2}

Simplify the radical expression

More Steps

x = \frac{128 \pm 2 4121}{2}

Separate the equation into 2 possible cases

x = \frac{128 + 2 4121}{2} x = \frac{128 - 2 4121}{2}

Simplify the expression

More Steps

x = 64 + 4121 x = \frac{128 - 2 4121}{2}

Simplify the expression

More Steps

x = 64 + 4121 x = 64 - 4121

Solution

x_{1} = 64 - 4121, x_{2} = 64 + 4121

Alternative Form

x_{1} \approx - 0.195015, x_{2} \approx 128.195015

Show Solution