First:
2x + 2z = 4
2(x+z)=4
x+z=4/2
x=2-z
-x - y - z= -8
-(2-z)-y-z= -8 replace x
-2+z-y-z= -8 (cancel z)
-2-y= -8
6 = y
Then:
-4x + 4y + 5z = 7 replace x and y
-4(2-z)+4*6 + 5z = 7
-8 + 4z + 24 + 5z = 7
16 + 9z = 7
9z = 7 - 16
9z = -9
z = -9/9
z= -1
Finally
x= 2-z replace z
x = 2- (-1)
x = 3
Let c and n represent the numbers of pencil and pen boxes, respectively
.. 3c +2n = 6.00
.. 2c +4n = 8.00
You can halve the second equation and subtract it from the first to get
.. (3c +2n) -(c +2n) = 6.00 -4.00
.. 2c = 2.00
.. c = 1.00
Then
.. 1.00 +2n = 4.00 . . . . . half the original second equation with c filled n
.. 2n = 3.00
.. n = 1.50
A box of pencils costs $1.00; a box of pens costs $1.50.
Answer:
D. 15
Step-by-step explanation:
Let the missing length be represented as x.
Thus:
(24 - x)/12 = x/20 => angle bisector theorem
Cross multiply
20(24 - x) = x(12)
480 - 20x = 12x
480 - 20x + 20x = 12x + 20x
480 = 32x
480/32 = 32x/32
15 = x
Missing length = x = 15
Using a system of equation, we have that:
a)
- x, which is the cost of on-site service.
- y, which is the cost of at-store service.
- z, which is the cost of by-mail service.
b)
The system is:



c)
The cost of one on-site repair service is of $90.
Item a:
The variables are:
- x, which is the cost of on-site service.
- y, which is the cost of at-store service.
- z, which is the cost of by-mail service.
Item b:
On-site service costs <u>3 times as much as at-store service</u>, thus:

By mail service costs <u>$10 less than at-store</u> service, thus:

Last week, the shop completed <u>15 services on-site, 40 services at-store, and 5 services by mail for total sales of $3100</u>, thus:

The system is:



Item c:
- The cost of one on-site repair service is x.
- First, replacing the first two equations into the third, we find y, and then with it we find x.






Then

The cost of one on-site repair service is of $90.
A similar problem is given at brainly.com/question/24823220
Answer:
294
Step-by-step explanation: