Answer:
Step-by-step explanation:
1
Answer:
3:9
Step-by-step explanation:
since there are 9 marbles in total it must be x to 9
the only solution available, which shows this is 3:9
If a is the first term then a+99*7=710, a+693=710, a=710-693=17. The first term is 17.
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: