Which values of c will cause the quadratic equation –x2 + 3x + c = 0 to have no real number solutions? check all that apply. –5 1

Hello :
the quadratic equation : ax²+bx+c = 0
when : a = -1    b = 3   c = c 
delta : Δ = b²-4ac  = 3² -4(-1)(c)
Δ = 9 + 4c 
to have no real number solutions when : Δ < 0 
so :  9 + 4c < 0 
c < -9/4 (values of c)

The answers 5 so there’s the you need trust me it’s right