X²+15x+36<0
at first solve quadratic equation
D=b²-4ac= 225-4*1*36= 81
x=(-b+/-√D)/2a
x=(-15+/-√81)/2= (-15+/-9)/2
x1=(-15-9)/2=-12
x2=(-15+9)/2=-3
we can write x²+15x+36<0 as (x+12)(x+3)<0
(x+12)(x+3)<0 can be 2 cases, because for product to be negative one factor should be negative , and second factor should be positive
1 case) x+12<0, and x+3>0,
x<-12, and x>-3
(-∞, -12) and(-3,∞) gives empty set
or second case) x+12>0 and x+3<0
x>-12 and x<-3
(-12,∞) and (-∞,-3) they are crossing , so (-12, -3) is a solution of this inequality
Answer:
12/67
Step-by-step explanation:
If you look at the chart, only 12 students that are male got a A. So the probability is 12 out of 67 students or approximately 18%.
5 - (3 x -7)
5 - (- 21)
5 + 21
26
Answer:
908.6
Step-by-step explanation:
64.9x 14
Answer:
About 5 hr 10 min
Step-by-step explanation:
rate 1 = 1 pool / 9 hrs rate 2 = 1 pool / 12 hours
now find the time with both rates combined
1 pool / ( 1/9 + 1/12) = 1/ (7/36) = 36/7 hr = 5 1/7 hr = 5 hr 8.6 min
