First write an equation system based on the problem
We can write "<span>Bread and sugar cost 110 together" as
</span>∴ b + s = 110
We can write "<span>bread cost 100 more than sugar" as
</span>∴ b = 100 + s
<span>
Second, solve the equation system by subtitution method
Subtitute b with (100+s) in the first equation, and we'll find the value of s
b + s = 110
(100 + s) + s = 110
100 + 2s = 110
2s = 110 - 100
2s = 10
s = 10/2
s = 5
The cost of the sugar is 5</span>
Answer:
first off here are the things you need to know:
She parked her car 4 levels below the street
so let's make that 4
and he doctor's office is at the fifth level of the building which makes it 5
so; 4+5=9 meaning she ride the elevator 9 levels
Answer:
Ron has 15 nickels and 9 quarters
Step-by-step explanation:
Create a system of equations where n is the number of nickels and q is the number of quarters he has:
n + q = 24
0.05n + 0.25q = 3
Solve by elimination by multiplying the top equation by -0.25
-0.25n - 0.25q = -6
0.05n + 0.25q = 3
Add them together and solve for n:
-0.2n = -3
n = 15
So, Ron has 15 nickels. Find how many quarters he has by subtracting 15 from 24:
24 - 15
= 9
So, Ron has 15 nickels and 9 quarters.
Answer:
Yes, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Step-by-step explanation:
H0 : σ² = 2.66²
H1 : σ² < 2.66²
X²c = (n - 1)*s² ÷ σ²
sample size, n = 40
Sample standard deviation, s = 1.9
X²c = ((40 - 1) * 1.9²) ÷ 2.66²
X²c = 140.79 ÷ 7.0756
X²c = 19.897
Using a confidence level of 95%
Degree of freedom, df = n - 1 ; df = 40 - 1 = 39
The critical value using the chi distribution table is 25.6954
Comparing the test statistic with the critical value :
19.897 < 25.6954
Test statistic < Critical value ; Reject the Null
Hence, we can conclude that the population standard deviation of TV watching times for teenagers is less than 2.66
Set up the following equations:
x represents car A's speed, and y represents car B's speed.
We'll use elimination to solve this system of equations. Multiply the first equation by 7:
Combine both equations:
Divide both sides by 28 to get x by itself:
The speed of car A is
80 mph.Since we now know the value of one of the variables, we can plug it into the first equation:
Subtract 160 from both sides.
Divide both sides by 2 to get y by itself:
The speed of car B is
60 mph.
