Answer:
C
Step-by-step explanation:
So we need to understand what is rational numbers?
Rational number which can be written under this form: 
when x any are both integers and y
The question here is : Which property would be useful in proving that the product of two rational numbers. In math, when we talk about the product of at least two number, it implies to the multiplication in the operation.
Here, only answer C: 
with the condition 
and a, b, c and d are integers. Product of two integers is always an integer..
Let cheese wafers = x
chocolate wafers = y
we know they bought 20 total packets so x+y = 20, this can be re-written as x = 20-y
cheese wafers cost 2, so we have 2x
chocolate wafers cost 1, so we have 1y, which is just the letter y
so we know 2x + y = $25
replace x with x=20-y to get:
2(20-y)+y = 25
distribute the parenthesis:
40-2y +y = 25
combine like to terms to get:
40-y = 25
subtract 40 from each side"
-y = -15
divide both sides by -1
y = 15
chocolate wafers was y so they bought 15 chocolate wafers
cheese wafers was x, so they bought 20-15 = 5 cheese wafers
using the substitution method was the easiest way to isolate one of the variables in order to find the solution.
Answer:
$168
Step-by-step explanation:
28x6
= 168
Answer:
300
Step-by-step explanation:
5 percent * 6000
(5:100)* 6000
(5* 6000):100
30000:100 = 300
Answer:
x = -2
Step-by-step explanation:
2x = -8+4
2x = -4
x = -2
CHECK
-4 - 4 = -8
