Question

(a) What should be added to x² + xy + y²to obtain 2x² + 3xy?

(b) What should be subtracted from 2a + 8b + 10 to get− 3a + 7b + 16?

Answer 1

(a) Let abe the required term.

a + (x² + y² + xy)= 2x² + 3xy
a = 2x²+ 3xy − (x² + y² +xy)

a = 2x² + 3xy − x²âˆ’ y² − xy

a = 2x² − x² −y² + 3xy − xy

= x² − y² + 2xy

(b) Let pbe the required term.

(2a + 8b + 10) − p = − 3a +7b + 16

p = 2a + 8b + 10 − (− 3a + 7b+ 16)

= 2a + 8b + 10 + 3a − 7b − 16

= 2a + 3a + 8b − 7b + 10−16

= 5a + b − 6