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..
Answer:
/yes
Step-by-step explanation:
Answer:
(1,2)
Step-by-step explanation:
x+4y = 9
2x -4y= -6
Add the equations together
x+4y = 9
2x -4y= -6
-------------------
3x +0y = 3
3x=3
Divide by 3
3x/3 = 3/3
x=1
Now find y
x+4y = 9
1 +4y =9
Subtract 1 from each side
4y = 8
Divide by 4
4y/4 = 8/4
y =2
Answer:
The measures of the angles at its corners are 
Step-by-step explanation:
see the attached figure to better understand the problem
step 1
Find the measure of angle A
Applying the law of cosines


![cos(A)= [215^{2}+125^{2}-185^{2}]/(2(215)(125))](https://tex.z-dn.net/?f=cos%28A%29%3D%20%5B215%5E%7B2%7D%2B125%5E%7B2%7D-185%5E%7B2%7D%5D%2F%282%28215%29%28125%29%29)


step 2
Find the measure of angle B
Applying the law of cosines


![cos(B)= [215^{2}+185^{2}-125^{2}]/(2(215)(185))](https://tex.z-dn.net/?f=cos%28B%29%3D%20%5B215%5E%7B2%7D%2B185%5E%7B2%7D-125%5E%7B2%7D%5D%2F%282%28215%29%28185%29%29)


step 3
Find the measure of angle C
Applying the law of cosines


![cos(C)= [125^{2}+185^{2}-215^{2}]/(2(125)(185))](https://tex.z-dn.net/?f=cos%28C%29%3D%20%5B125%5E%7B2%7D%2B185%5E%7B2%7D-215%5E%7B2%7D%5D%2F%282%28125%29%28185%29%29)

