the cost of bottles of water is $6. which expression shows how to find the cost of 10 bottles of water

Tomas is making trail mix using granola and walnuts. he can spend a total of $12 on the ingredients. he buys 3 pounds of granola that costs $2.00 per pound. the walnuts cost $6 per pound. he uses the equation to represent the total cost, where x represents the number of pounds of granola and y represents the number of pounds of walnuts. he solves the equation for y, the number of pounds of walnuts he can buy. answer- b tomas added 6 to both sides of the equation instead of subtracting 6. just took the test

Me. i can't figure out this question. give an explanation too. .

The owner of the plant nursery where you were tells you to fill 350 ml bottles from a 30 l from a fertilizer