Answer:
The infant mortality rate in Korea based on equality provided is:
Step-by-step explanation:
Since the text mentions that the infant mortality rate in Korea is equal to the criminal success rate, the two expressions must equalize and clear the variable m, which is the rate in each of the expressions:
- 7 (m + 3) - 2 = 8m + 17.2
- 7m + 21 - 2 = 8m + 17.2
- 7m + 19 = 8m + 17.2
- 19 - 17.2 = 8m - 7m
- 1.8 = m
As you can see, once the equality of the expressions is solved, <u>a rate of 1.8</u> is obtained.
Number of weekend minutes used: x
Number of weekday minutes used: y
This month Nick was billed for 643 minutes:
(1) x+y=643
The charge for these minutes was $35.44
Telephone company charges $0.04 per minute for weekend calls (x)
and $0.08 per minute for calls made on weekdays (y)
(2) 0.04x+0.08y=35.44
We have a system of 2 equations and 2 unkowns:
(1) x+y=643
(2) 0.04x+0.08y=35.44
Using the method of substitution
Isolating x from the first equation:
(1) x+y-y=643-y
(3) x=643-y
Replacing x by 643-y in the second equation
(2) 0.04x+0.08y=35.44
0.04(643-y)+0.08y=35.44
25.72-0.04y+0.08y=35.44
0.04y+25.72=35.44
Solving for y:
0.04y+25.72-25.72=35.44-25.72
0.04y=9.72
Dividing both sides of the equation by 0.04:
0.04y/0.04=9.72/0.04
y=243
Replacing y by 243 in the equation (3)
(3) x=643-y
x=643-243
x=400
Answers:
The number of weekends minutes used was 400
The number of weekdays minutes used was 243
