Solve 4x^2-20x=4200

Question

Solve the quadratic equation

Solve by factoring

Solve using the quadratic formula

Solve by completing the square

x_{1} = - 30, x_{2} = 35

Evaluate

4 x^{2} - 20 x = 4200

Move the expression to the left side

4 x^{2} - 20 x - 4200 = 0

Factor the expression

More Steps

Evaluate

4 x^{2} - 20 x - 4200

Rewrite the expression

4 x^{2} - 4 \times 5 x - 4 \times 1050

Factor out 4 from the expression

4 (x^{2} - 5 x - 1050)

Factor the expression

More Steps

Evaluate

x^{2} - 5 x - 1050

Rewrite the expression

x^{2} + (30 - 35) x - 1050

Calculate

x^{2} + 30 x - 35 x - 1050

Rewrite the expression

x \times x + x \times 30 - 35 x - 35 \times 30

Factor out x from the expression

x (x + 30) - 35 x - 35 \times 30

Factor out - 35 from the expression

x (x + 30) - 35 (x + 30)

Factor out x + 30 from the expression

(x - 35) (x + 30)

4 (x - 35) (x + 30)

4 (x - 35) (x + 30) = 0

Divide the terms

(x - 35) (x + 30) = 0

When the product of factors equals 0,at least one factor is 0

x - 35 = 0 x + 30 = 0

Solve the equation for x

More Steps

Evaluate

x - 35 = 0

Move the constant to the right-hand side and change its sign

x = 0 + 35

Removing 0 doesn't change the value,so remove it from the expression

x = 35

x = 35 x + 30 = 0

Solve the equation for x

More Steps

Evaluate

x + 30 = 0

Move the constant to the right-hand side and change its sign

x = 0 - 30

Removing 0 doesn't change the value,so remove it from the expression

x = - 30

x = 35 x = - 30

Solution

x_{1} = - 30, x_{2} = 35

Show Solution