Step-by-step explanation:
24x+72-2
C.24x+70.........
3x+2y=11
y=5x-1
Substitute the y in the first equation:
3x+2(5x-1)=11
y=5x-1
3x+10x-2=11
y=5x-1
13x=13
y=5x-1
Now substitute the x to find the y:
x=1
y=5-1=4
Try this suggested example.
PS. the 1st step is marked with red, the 2d step - with green, the 3d step - with blue colours, then the final step is marked with orange.
Answer:
The answers are:
a)
is FALSE.
b)
is TRUE.
c)
is FALSE.
d)
is FALSE.
e)
is FALSE.
f)
is TRUE.
g)
is FALSE.
h)
is FALSE.
Step-by-step explanation:
We can show that the FALSE statement are, in fact, false finding an example where the equality fails.
a) Take x=2 and y=3 and notice that (2+3)² = 25, while 2²+3²=4+9=13.
b) (x+y)² = (x+y)(x+y)=x²+xy+xy+y² = x² +2xy +y².
c) Take x=2 and y=3 and notice that 2/(2+3) = 2/5 which is different from 1/3.
d) Take x=2 and y=3 and notice that 2-(2+3) = 2-5=-3 which is different from 3. Recall that x-(x+y) = x-x-y=-y.
e) Take x=-2, and notice that [tax]\sqrt{(-2)^2} = \sqrt{4} = 2[/tex] which is different from -2.
f) The previous example illustrate why this is true.
g) Take x=1, and notice that
which is different from 3.
h) Take x=2 and y=3 and notice that 1/(2+3)=1/5 and 1/3+1/2 = 5/6.
675 people will have score between 85 and 120
Step-by-step explanation:
Given
Mean = 100
SD = 15
If we have to find percentage of score between two values we have to find the z-score for both values and then area under the curve for both values
z-score is given by:
for a value x:

So,
For 85:


Now we have to find the area under the curve for both values of z-score. z-score tables are used for this purpose.
So,
For z1 : 0.1587
For z2: 0.9082
The area between z11 and z2:

So the probability of score between 85 and 120 is 0.7495
As the sample is of 900 people, the people with scores between 85 and 120 will be:
900*0.7495 = 674.55 people
Rounding off to nearest whole number
675 people will have score between 85 and 120
Keywords: Probability, SD
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