Add them 2 equations to eliminate x's
-2x-y=9
<u>2x-9y=1 +</u>
0x-10y=10
-10y=10
divide by -10
y=-1
sub back
-2x-y=9
-2x-(-1)=9
-2x+1=9
-2x=8
divide by -2
x=-4
y=-1
(x,y)
(-4,-1)
A
<u>
</u>
Answer:
The length is 48
The width is 20
Step-by-step explanation:
When 2 rectangles (figures) are similar, the ratio of corresponding sides are equal.
This rectangle is 5 by 12, so the shorter side (corresponding to 5) to the longer side (corresponding to 12) would be the same ratio, 5:12.
Let shorter side be s, and
longer side be l
It says, long side is 8 greater than twice short, we can write this as:

In similar rectangles, we have said the corresponding sides' ratio are equal, so we could write:

Now, we replace the new found expression for "l" onto this and cross multiply and solve for s first:

So the shorter side is 20. and hence the longer side would be:
l = 2s + 8
l = 2(20) + 8
l = 40 + 8
l = 48
The longer side is 48.
The length is 48
The width is 20
Answer:
C. He should run a T-test, and approximating it with a normal distribution would be inappropriate.
Step-by-step explanation:
We are told that the standard deviation is unknown.
Now in statistics, when we know the standard deviation, then we use a Z-test but when we don't know the standard deviation, then we will use a t-test.
Now, the t-test assumes a normal distribution for difference in mean of samples but it doesn't assume so for population.
Thus, we will run a t-test and doesn't need to approximate with a normal distribution.
We are given:

To simplify this inequality, we can add 2 to all three sides. When we do that, we are left with:

After we simplify that, we can divide all sides by -6. Here is what we get:

When you simplify, your final answer will be:

Answer:
90
Step-by-step explanation:
90