Question

13. What must be added to a + 2b to get b - 2a?​

Answer 1

let the required expression be x

a + 2b + x = b - 2a

x = (- 2a + b) - (a + 2b)

x = - 3a + 3b

so the required expression is 3a + 3b.

Answer 2

Answer:

Heya mate!!

Answer refers in the attachment above.

Hope it helps u dear.✌️✌️