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:
Just substitute each number in for the variables: 9 for m and 3 for n.
2m+2n
= 2(9)+2(3)
= 18+6
= 24
Answer:
(a+b)^2+(a-b)^2=2(a^2+b^2)
expanding:
a² + 2ab + b² + a² -2ab + b² = 2a² + 2b²
2a² + 2b² = 2a² + 2b²
Answer:
Step-by-step explanation:
The area formula for a parallelogram is base*height=area. Make an equation. You know the area and the height, so plug that into the equation, and you get x*18=396. Solve for x by dividing 396 by 18 and you get 22. So, the base is 22cm.
