Answer:
l = 2.25 cm
Step-by-step explanation:
given l is inversely proportional to w² then the equation relating them is
l = 
← k is the constant of proportion
(i)
to find k use the condition w = 1.5 , l = 16 , then
16 = 
= 
( multiply both sides by 2.25 )
36 = k
l = 
← equation of proportion
(ii)
when w = 4 , then
l = 
= 
= 2.25 cm
Part A:
We see that this pair of equations has 1 solution. On a graph, the solutions of 2 (or more) lines is where the lines intersect. In this case, since these lines intersect 1 time, they have 1 solution.
Part B:
As previously mentioned, the solutions of multiple lines is where the lines intersect. In this case, since they intersect at (4,4), that is the solution.
Negative, Nonlinear,
I hope this helped:)
The discount is 50-14 = $36
% discount = (36/50)*100 = 72%
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
