Answer:
I believe the answer is A - graph W
Step-by-step explanation:
Answer:
(1,2)
Step-by-step explanation:
x+4y = 9
2x -4y= -6
Add the equations together
x+4y = 9
2x -4y= -6
-------------------
3x +0y = 3
3x=3
Divide by 3
3x/3 = 3/3
x=1
Now find y
x+4y = 9
1 +4y =9
Subtract 1 from each side
4y = 8
Divide by 4
4y/4 = 8/4
y =2
Answer:
D. The students are not part of the population
Step-by-step explanation:
The first three options are true of this sample. D is the only option that is not true.
Answer:
3
Step-by-step explanation:
4(x + 1) + 8 = 24
Subtract 8 from each side
4(x + 1) + 8-8 = 24-8
4(x + 1) = 16
Divide by 4
4(x+1)/4 = 16/4
x+1 = 4
Subtract 1
x+1-1 = 4-1
x=3
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