Solve x^2-21=4x - ScanMath

Evaluate

x^{2} - 21 = 4 x

Move the expression to the left side

x^{2} - 21 - 4 x = 0

Factor the expression

More Steps

(x - 7) (x + 3) = 0

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

x - 7 = 0 x + 3 = 0

Solve the equation for x

More Steps

x = 7 x + 3 = 0

Solve the equation for x

More Steps

x = 7 x = - 3

Solution

x_{1} = - 3, x_{2} = 7

Solve the quadratic equation