Question

(b) What should be added to the sum of 18x + 19y and 13xy + 12x to get 17xy-11y​

Answer 1

4xy - 30y - 30x

Explanation:

Lets say a=answer

Solve for a:

(18x + 19y) + (13xy + 12x) + a = 17xy-11y​

18x + 19y + 13xy + 12x + a = 17xy-11y​

18x + 12x + 19y + 13xy + a = 17xy-11y​

30x + 19y + 13xy + a = 17xy-11y​

30x + 19y-19y + 13xy + a = 17xy-11y​ - 19y ==> subtract 19y on both sides

30x + 13xy + a = 17xy-30y

30x + 13xy-13xy + a = 17xy-13xy-30y ==> subtract 13xy on both sides to

isolate a

30x + a = 4xy-30y

30x - 30x = 4xy - 30y - 30x ==> subtract 30x on both sides to isolate a

a = 4xy - 30y - 30x ==> simplify