You’re trying to get the first equation to equal y so you can substitute it in the second question
2x + y = -2
subtract 2x from both sides: y = -2 - 2x
rearrange the equation : -2x -2
so the answer is C
Answer:
105 boys
Step-by-step explanation:
At a local preschool there is a ratio of 3 boys to 4 girls.
i.e boys:girls = 3:4
There are 245 preschoolers enrolled.
Number of boys =
× 245 = 105 boys
Answer:
H0 : σ²= 7.2²
H1 : σ² < 7.2
We can conclude that the mean waiting time of customers vary less, Than 7.2 minutes.
Step-by-step explanation:
H0 : σ²= 7.2²
H1 : σ² < 7.2²
The test statistic :
X² = [(n - 1)*s² ÷ σ²]
s² = 3.5
n = sample size = 25. ; s²
X² = [(25 -1)*3.5² ÷ 7.2²
X² = (24 * 3.5^2) / 7.2^2
X² = 5.67
Pvalue from Chisquare statistic :
P(X² < 5.67) = 0.000042
Pvalue < α ; we reject the Null.
Hence, we can conclude that the mean waiting time of customers vary less, Than 7.2 minutes.
Answer:
D.) f(m)=27−3m
Step-by-step explanation:
Given that:
Original rating = 27
Total possible rating points = 30
Drop in rating point per month = 3
m = number of months since release :
Hence,
F(m) = original rating - drop in rating per month * number of months since release
F(m) = 27 - 3(m)
F(m) = 27 - 3m
1. 5m+3n=41
3m-6n=9 (multiplying the first equation by 3 and the second by 5), we get;
15m+9n=123
15m-30n= 45 (subtracting the two equations)
39n = 78
n = 2, and
to get m we substitute n with 2
3m = 9+6(2)
3m = 21
m = 7
Therefore, n=2 and m=7
2. 6g +8h=40
-6g +2h = -20(Adding the two equations to eliminate g)
10 h= 20
h =2
to get g we substitute h with two
6g= 40- 8(2)
= 24
g= 4
Therefore, g =4 and h =2
3. 9x +5y =35
2x + 5y =0 (subtracting the two equations to eliminate y)
7x =35
x= 5
To get y we substitute x with 5
5y=35-9(5)
5y = -10
y = -2
Therefore, x=5 and y=-2