Correct question is;
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 2x + 6y = 12 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.
2x + 6y = 12
2(3) + 6y = 12
6 + 6y + 6 = 12 + 6
6y = 18
y = 3
which is the first error that tomas made?
A) tomas substituted the 3 for x when he should have substituted 6 for x.
B) tomas added 6 to both sides of the equation instead of subtracting 6.
C) tomas should have written the equation as 3x + 6y = 12.
D) tomas substituted 3 for x when he should have substituted 3 for y.
Answer:
Option B: tomas added 6 to both sides of the equation instead of subtracting 6.
Explanation:
We are told that; x represents the number of pounds of granola while y represents the number of pounds of walnuts.
Now, we are told that He can spend a total of $12 on the ingredients. Also that he buys 3 pounds of granola that costs $2.00 per pound while the walnuts cost $6 per pound.
Thus;
2x + 6y = 12
He buys 3 pounds of granola. Thus;
2(3) + 6y = 12
6 + 6y = 12
The next step here is to subtract 6 from both sides but Tomas added 6 to both sides instead.
Thus, option B is the correct answer.