Apples are worth a=1 and bananas b=2 I end with x2=4 apples and y2=5 bananas Thus i have a total of p2=9 Worth a total of t2=14 p1 is the total number of fruits (x1 + y1) t1 is the total value of fruits (equal to t2=14) we know that initially: x1 = k(p1) (where k=0.6) x1 = k(x1 + y1) (1/k)x1 = x1 + y1 ((1/k)-1)x1 - y1 = 0 some other things we know: x1(a) + y1(b) = t1 x1(1) + y1(2) = 14 so now we just have some sim equations: x1((1/k)-1) - y1(1) = 0 x1(a) + y1(b) = t1 let's flip the bottom row: x1((1/k)-1) - y1(1) = 0 -x1(a) - y1(b) = -t1 and devide by b=2 x1((1/k)-1) - y1 = 0 x1(-a/b) - y1 = -t1/b and join the two: -x1(a) - y1(b) + 14 = 0 ... x1((1/k)-1) - y1 = x1(-a/b) - y1 + (t1/b) then we can drop y1: x1((1/k)-1) = x1(-a/b) + (t1/b) and reduce: x1((1/k)-1+(a/b)) = (t1/b) and again: x1 = (t1/b) / ((1/k)-1+(a/b)) so: x1 = (14/2) / ((1/0.6)-1+(1/2)) x1 = 6 and then we know that: x1(a) + y1(b) = t1 6(1) + y1(2) = 14 y1(2) = 14 - 6(1) y1 = (14 - 6(1)) / 2 y1 = 4 so now we know: x1 = 6 y1 = 4