How do i find the exact length of side a and b how do i know what the area of abc are here are the coordinates a (-2,4) b (0,1) c(1,-3) me

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

Having a hard time understanding this question (see attachment).

Tell whether the two rates form a proportion