Answer:
x = 5, y = -2
Step-by-step explanation:
2x + 5y = 0 --- Equation 1
Equation 1×3: <u>6x</u> + 15y = 0 --- Equation 2
3x - 4y = 23 --- Equation 3
Equation 3×2: <u>6x</u> - 8y = 46 --- Equation 3
<em>We will be eliminating 6x from Equation 2. </em>
Equation 3-2: 6x - 8y - 6x - 15y = 46-0
-23y = 46
y = 46 ÷ -23
<u>y = -2 </u>
Substitute y = -2 into Equation 1:
2x + 5y = 0
2x + 5(-2) = 0
2x + (-10) = 0
2x - 10 = 0
2x = 10
x = 10 ÷ 2
<u>x = 5 </u>
Answer:
D
Step-by-step explanation:
You have to be careful that you treat 21 as special. It is the only positive number. As you do the problem, keep an eye on 21.
f(-2) = 3x^2 - 2x + 5 Put -2 wherever you see an x
f(-2) = 3(-2)^2 - 2(-2) + 5 Calculate the first term.
f(-2) = 3(4) - 2(-2) + 5 Remove the brackets of the second term
f(-2) = 12 + 4 + 5 Combine
f(-2) = 21
I say the answer is point c from the way the points are on the graph
Answer:
That probability is 0.1838 or 18.4% or enter 18.4
Step-by-step explanation:
mean 35 sd 5
20 is 3 sd s to the left of the mean
30 is 1 sd to the left.
The empirical rule has 68% within 1 sd or 34% on one side
It has 95% within 2 sd or 47.5% on one side
It has 99.7% within 3 sd or 49.85% on one side
Therefore between 3 sd and 1 sd on one side is 49.85-34=15.85% or enter 15.9
mean of 48 sd 7
between 48 and 55 is between -1 and 0 sd or 34% enter 34. The last one doesn't seem to post easily:z=(x-mean)/sd or z< (1217-1481)/293 or z <-264/293 or -0.901,
That probability is 0.1838 or 18.4% or enter 18.4