Answer:
Multiply the first equation by 4.
Step-by-step explanation:
4(x+y=3) which gives
4x+4y=12
and
4x-y=7
Then subtract the two equations and the x variable will be eliminated.
Answer:
The inequality is 
The greatest length of time Jeremy can rent the jet ski is 5 and Jeremy can rent maximum of 135 minutes.
Step-by-step explanation:
Given: Cost of first hour rent of jet ski is $55
Cost of each additional 15 minutes of jet ski is $10
Jeremy can spend no more than $105
Assuming the number of additional 15-minutes increment be "x"
Jeremy´s total spending would be first hour rental fees and additional charges for each 15-minutes of jet ski.
Lets put up an expression for total spending of Jeremy.

We also know that Jeremy can not spend more than $105
∴ Putting up the total spending of Jeremy in an inequality.

Now solving the inequality to find the greatest number of time Jeremy can rent the jet ski,
⇒ 
Subtracting both side by 55
⇒ 
Dividing both side by 10
⇒
∴ 
Therefore, Jeremy can rent for 
Jeremy can rent maximum of 135 minutes.
Answer: The second option (160 cm)
Step-by-step explanation:
1. You can obtain the perimeter of a quadrilateral by adding the lenghts of the sides.
2. You know that the ratio of the side lengths is 3:3:5:8 and the perimeter is 380 centimeters.
3. Therefore, you can write the following expression, where x is an integer:

4. Solve for x:

5. Therefore, the longest side is:
(160 cm)
Ok, first let's multiply:
3 x 1/6 = 3/6 (simplify:) 1/2
Then multiply again:
3 x 1/9 = 3/9 (simplify:) 1/3
Now the expression is simplified to (1/2x, 1/2y)
Hope this helped! Please comment or DM me if you have anymore questions or don't understand :)