x2 - 7x = -13

Question

Solve x2 - 7x = -13.

x equals quantity of negative 7 plus or minus I square root of 6 all over 2

x equals quantity of negative 7 plus or minus I square root of 3 all over 2

x equals quantity of 7 plus or minus I square root of 6 all over 2

x equals quantity of 7 plus or minus I square root of 3 all over 2

Answer 1

x² - 7x + 13 = 0

 

This quadratic does not factor, so use the quadratic formula to find x:

 

x = (-b/2a) ± (1/2a)√(b²-4ac)

 

In your equation, a=1, b=-7, and c=13:

 

x = (-(-7)/2) ± (1/2) √[(-7)²-4(1)(13)]

 

x = (7 ± i√3)/2