Question

Which of the following is the solution to the quadratic equation
x2−10x+21=0 ?

Answer 1

Explanation:

the answer is the image above

Answer 2

x=3 and x=7

Explanation:

x2 - 10x + 21=0

a=1, B=-10, c=21

delta= b2 - 4(ac)

if delta >0 => have two answer

x1= -b - _/delta / 2a = -(-10) - _/16 / 2.1 = 3

x2= -b + _/delta /2a = -(-10) + _/16 / 2.1= 7