Answer:the company bought 12 computers and 4 printers.
Step-by-step explanation:
Let x represent the number of computers that the company bought.
Let y represent the number of printers that the company bought.
The company buys a total of 16 machines. It means that
x + y = 16
Each computer costs $550 and each printer costs $390. If the company spends $8160 for all the computers and printers that was bought, it means that
550x + 390y = 8160 - - - - - - - - - - 1
Substituting x = 16 - y into equation 1, it becomes
550(16 - y) + 390y = 8160
8800 - 550y + 390y = 8160
- 550y + 390y = 8160 - 8800
- 160y = - 640
y = - 640/ - 160
y = 4
Substituting y = 4 into x = 16 - y, it becomes
x = 16 - 4
x = 12
Answer:
hotdog $1, and hamburger $2
Step-by-step explanation:
D-is hot dogs, H-hamburgers
7D +4H = 15
4D +7H = 18
we got 2 equations with 2 unknown so we can solve
7D +4H = 15 multiply by 7
4D +7H = 18 multiply by -4
49D +28H = 105
-16D -28H = -72 add the two equations
33D= 33 so D=$1
go back to the first equation:
7*1 +4H =15 gives us 4H = 15-7; 4H = 8 so H= $2
218 Students
109 Adults
Let x = adults
Let 2x = students
Add together and set equal to the total number.
Total students: 5 + 6 + 2 = 13
Total students fluent or a beginner: 5 + 2 = 7
Probability of picking 1 fluent or beginner = total of fluent or beginner over total students:
7/13
