5n2+100=30n , need explaining how you would work this out

n = 3 + i√11 ,  3 - i√11

Step-by-step explanation:

This is a quadratic equation  and the first step is to write it in standard form:

5n^2 - 30n + 100 = 0

Divide through by 5:

n^2 - 6n + 20 = 0

Completing the square:-

(n - 3)^2 - 9 + 20 = 0

(n - 3)^2 = -11

n - 3 = i√11 or - i√11

n = 3 + i√11 ,  3 - i√11

(2 complex roots).

c.

step-by-step explanation:

she should of added 9^2 and 12^2. that is because it is a^2+b^2=c^2. c^2 is the hypotenuse and should always be bigger than the other two numbers. which is why she should of added 9 squared and 12 squared together instead of 15 squared.