Let n = cost of 1 notebook
Let p = cost of 1 pencil
Then,
3n + 4p = 8.5
5n + 8p = 14.5
You can solve for one variable in terms of the other and then substitute into the remaining equation.
3n + 4p = 8.5
+ 5n + 8p = 14.5
Multiply the top equation by -2 so that the p-containing terms cancel each other out:
-2(3n + 4p = 8.5)
+ 5n + 8p = 14.5
-n + 0 = -2.5
So after dividing both sides by -1, we see that n = $2.5. Plugging into the first equation gives p = $0.25.
3n + 4p = 8.5
5n + 8p = 14.5
Answer:
Step-by-step explanation: 2 is the real population
Answer:
x=10, y=-5
Step-by-step explanation:
2x+3y=5, y= 5-x; change y to 5-x:
2x+3(5-x)=5
2x-3x+15=5
-x=5-15
-x=-10
x=10
=>y=5-x=5-10=-5
Answer:
75.36 inches
Step-by-step explanation:
C = π·d
C = 3.14(24)
C = 75.36
The correct answer is B
These students do not represent the whole population of students, so the results of the survey will disproportionately recognize the opinion of the extracurricular students.