Question

Solve for a: a(a-3) =100

Answer 1

`a(a-3) =100\\ a^2-3a-100=0\\ \Delta=(-3)^2-4\cdot1\cdot(-100)=9+400=409\\ √(\Delta)=\sqr{409}\\ a_1=(-(-3)-√(409))/(2\cdot1)=(3-√(409))/(2)\\ a_2=(-(-3)+√(409))/(2\cdot1)=(3+√(409))/(2)`