Solve (5x-8) (4x 8)=90

Question

Solve the quadratic equation

Solve using the quadratic formula

Solve by completing the square

Solve using the PQ formula

x_{1} = \frac{16 - 481}{20}, x_{2} = \frac{16 + 481}{20}

Alternative Form

x_{1} \approx - 0.296586, x_{2} \approx 1.896586

Evaluate

(5 x - 8) (4 x \times 8) = 90

Remove the parentheses

(5 x - 8) \times 4 x \times 8 = 90

Multiply the terms

More Steps

32 x (5 x - 8) = 90

Expand the expression

More Steps

160 x^{2} - 256 x = 90

Move the expression to the left side

160 x^{2} - 256 x - 90 = 0

Substitute a= 160,b= - 256 and c= - 90 into the quadratic formula x = \frac{- b \pm b ^{2} - 4 a c}{2 a}

x = \frac{256 \pm ( - 256 ) ^{2} - 4 \times 160 ( - 90 )}{2 \times 160}

Simplify the expression

x = \frac{256 \pm ( - 256 ) ^{2} - 4 \times 160 ( - 90 )}{320}

Simplify the expression

More Steps

x = \frac{256 \pm 123136}{320}

Simplify the radical expression

More Steps

x = \frac{256 \pm 16 481}{320}

Separate the equation into 2 possible cases

x = \frac{256 + 16 481}{320} x = \frac{256 - 16 481}{320}

Simplify the expression

More Steps

x = \frac{16 + 481}{20} x = \frac{256 - 16 481}{320}

Simplify the expression

More Steps

x = \frac{16 + 481}{20} x = \frac{16 - 481}{20}

Solution

x_{1} = \frac{16 - 481}{20}, x_{2} = \frac{16 + 481}{20}

Alternative Form

x_{1} \approx - 0.296586, x_{2} \approx 1.896586

Show Solution