algebra 1 pls respond ASAP

Question

 

1. Unleaded gas and supreme gas sell for different prices per liter. Suppose that 2 liters of unleaded gas and 3 liters of supreme gas cost a total of $2.52. Five liters of unleaded gas and 4 liters of supreme gas cost a total of $4.48.
2. What is the price per liter of each kind of gas?
3. If Ted filled his pickup with 30 liters of unleaded gas and also filled his car with 25 liters of supreme gas, how much would he have to pay for the gas? Assume prices have not changed.

Answer 1

2u + 3s = 2.52

5u + 4s = 4.48

Looks like we should solve this with elimination, where we get u or s to cancel out. I'll pick u. The LCM of 2 and 5 is 10, but we need one to be -10 to cancel out, soooo I'm gonna multiply the top by 5 and the bottom by -2.

10u + 15s = 12.6

-10u - 8s = -8.96

Now, we add the two together.

7s = 3.64

s = $0.52, aka 52 cents

Now, hopefully you know how to find the rest. Go!