Answer:
x=9
y=3
Step-by-step explanation:
since all three sides of an equlateral triangle are equal:
3x+y=30 then y=30-3x
4x-2y=30
4x-2(30-3x)=30
4x-60+6x=30
10x=90
x=9
3x+y=4x-2y
x=3y
y=3
Answer:

Step-by-step explanation:

Hi there, your picture in incomplete! Its cut off so we can't view the rest of it :)
I think is a because if you see and do it you could see
X = gym memberships, and y = bottles of water
30x + 7y = 1050.....when x = 28
30(28) + 7y = 1050
840 + 7y = 1050
7y = 1050 - 840
7y = 210
y = 210/7
y = 30....so he would have to sell 30 water bottles