Answer:
2 Answers By Expert Tutors ... Let's set x = cost of books and y = cost of pens. ... In algebra, this can be written as x + y = 18. ... Using x and y, we get 1 book and 2 pens costs $21, or x + 2y = 21 ... The pen must cost $3 because we are adding $3 to the total when we ... Please provide a valid phone number.
Step-by-step explanation:
Using a system of equations, it is found that the correct option is:
A) 1389x+1660y=787x+1121y.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, considering the amounts in each olympics(1389 men and 787 women participated on the 19th, 1660 men and 1121 women in the 22th), the system is:
A) 1389x+1660y=787x+1121y.
More can be learned about a system of equations at brainly.com/question/24342899
Answer:
9
Step-by-step explanation:
8X+4=360-108-80-96
8X+4=76
8X=76-4
8X=72
X=72/8
X=9
Answer:
b
Step-by-step explanation:
Answer:
so 1/3 must be subtracted from the sum of 1/4 and 1/6 to have an average of 1/12 of all the two fractions.
Step-by-step explanation:
let the fraction be x
(1/4 + 1/6)-x = 1/12
or, 10/24 - x = 1/12
or, 5/12-1/12 = x
so, x = 4/12 = 1/3
