Let rs.5 denominations be x , then rs 10 denominations will be 90-x
then total amount 5x + 10(90-x) which is rs.500
5x + 10(90-x) = 500
900 - 5x = 500
400 = 5x
therefore x = 80
therefore no. of rs.5 is 80
no. of rs.10 is 90-x = 90-80 = 10
Answer:

Step-by-step explanation:
Use distributive property: 
What is -x * x^2? Answer: -x^3
What is 3 * x^2? Answer: +3x^2
What is -x * -4x? Answer: +4x^2
What is 3* -4x? Answer: -12x
What is -x * -6? Answer: +6x
What is 3 * -6? Answer: -18

Combine like terms, and your answer would be....

Hope this helps :)
Have a great day!
Answer:
the answer would be C
Step-by-step explanation:
The answer would be 30in.
Reasoning: if the two figures are proportional, you would set it up in a proportion. It would be 36/x=12/10. Then cross multiply, so it would be 12x and 36(10). Afterwords you’ll have 12x=360, then divide both sides by 12 and you’ll end up with 30.