a + b + c = 30 ;
a = 6c ;
a = 2b ;
Then, c = a / 6 and b = a / 2 ;
a / 6 + a / 2 + a = 30 ;
a / 6 + 3a / 6 + 6a / 6 = 180 / 6 ;
10a = 180 ;
a = 18 ;
b = 9 ;
c = 3.
Good luck !
Answer:
15.
16. 10 ml of 20% saline and 40 ml of 10% saline
Step-by-step explanation:
A chemist takes x ml of 20% saline and y ml of 10% saline. In total, he takes
x + y ml that is 50 ml, so
There are 
ml of salt in x ml of 20% saline and 
ml of salt in 10% saline. There are 
ml of salt in 50 ml of 12% saline. Thus,
15. We get the system of two equations:
16. Solve this system. From the first equation:
Substitute it into the second equation:
No because the exact opposite of -3 would be 3.
If i'm not wrong its distributing property of addition. <span />
Answer:
Emma was right to say that both packages are close to 2 pounds.
If we round-off the weights of both to the nearest whole number we would get 2 pounds on both. We look at the the difference of both from 2 pounds we get the following:
2.36 - 2.0 = 0.36
2.09 - 2.0 = 0.09
The smaller the difference the closer it is to the base value. So we can say that the closest one is 2.0 pounds is the package that weighs 2.09 pounds.
