Omas 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. Which is the first error that Tomas made?

The answer is "Tomas added 6 to both sides of the equation instead of subtracting 6".

Step-by-step explanation:

In the question the equation is missing which can be defined as follows:

Missing equation:

When x=3

In the above equation if we add 6, by this the equation doesn't affect:

for this case we must apply distributive property to the following expression:

the distributive property states that:

then, when applying the property we have to multiply the -2 for each term within the parenthesis: