Question 171190
if f(x)=ax^2+bx+c then
f has a solution if d=b^2-4ac >=0

s^2 - 4s + 4 = 0 
d= (-4)^2-4(1)(4)=0 (has a solution with multiplicity 2)

5/6x2 - 7x - 6/5 = 0

d= (-7)^2-4(5/6)(-6/5)=53 (has 2 solutions)

	7a2 + 8a + 2 = 0

d= 8^2-4(7)(2)=8 (has 2 solutions)