i will fill the boxes from top down
4(-2)-5=-13
4(1)-5=-1
4(2)-5=3
4(3)-5=7
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:

A. 15-35=-20
b. -2+7=5
c. -10+14=4
d. 60-100=-40
15. A=7, 16. V=9, 17. D=26