A. X^2 + 5X >-6 you can see that X can be all positive including 0 so not finite
B. this shows X has to be >3 and <-7 so again not finite
C. move terms around gets 6x < 21 so x can be any negative value and couple of positives so infinite
D. x^2 - 4x <-3 You can readily see that X cant be negative since the -4X and x^2 results in positives thus invalidates the inequality. Try plugin couple of numbers - 0 doesnt work since 0<-3 is invalid. X=1 gets you -3<-3 so no. x=2 gets you 4-8 = -4<-3 which works x=3 gets 9-12=-3 <-3 so no. Stop here and you see x can be only 2
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