Answer:

Step-by-step explanation:
This system of equations is convenient, because the second equation already expresses y in terms of x. Now, you can substitute that in.

Multiplying both sides by -1 and bringing the 5 over:

Combining like terms and factoring out 5:

Factoring:

Solutions: 
Hope this helps!
Answer:
22123
Step-by-step explanation:
→ Find the multiplier
3% decrease = 0.97
→ Multiply the population by the multiplier which is to the power of years
30000 × 0.97¹⁰ = 22122.7 = 22123
Step-by-step explanation:
Charges per page = $0.08
Amount Lionel paid = $20.00
No of pages = 20 ÷ 0.08 = 250 pages