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
<span>Exponent
is a number used to express shorter equation; it is a number that says how many
times you are going to multiply the base number.
</span><span>
Exponents have several laws, here are
some:
=> x^1 = x
=> x^0 = 1
=> x^-1 = 1/x
=> x^m x^n = X^m+n
=> x^m/x^n = x^m-n
And since we were asked to write an
expression with a negative exponent that has a value between 0 and ½
=> 2^ -2 = ½
</span>
5x+19=6x+1 because of parallel postulate.
x=18
Answer:
96 questions
Step-by-step explanation:
Given that:
Total number of questions = 120
Percentage questions completed = 80%
Number of questions completed =?
Number of questions completed = total number of questions * percentage questions completed
Number of questions completed = 120 * 0.8
Number of questions completed = 96
