Question

Add:
(i) 3x, 7x
(ii) 7y, −9y
(iii) 2xy, 5xy, −xy
(iv) 3x, 2y
(v) 2x², − 3x², 7x²
(vi) 7xyz, − 5xyz, 9xyz, −8xyz
(vii) 6a³, − 4a³, 10a³, −8a³
(viii) x² − a², −5x² + 2a², −4x² + 4a²

Answer 1

(i) Required sum = 3x + 7x
= (3+7)x = 10x

(ii) Required sum = 7y +(−9y)
= (7-9)y = -2y

(iii) Required sum = 2xy +5xy + (−xy)
= (2+5-1)xy = 6xy

(iv) Required sum = 3x+2y

(v) Required sum = 2x² + (− 3x²) + 7x²
=(2-3+7)x² = 6x²

(vi)Required sum = 7xyz + (− 5xyz) + 9xyz + (−8xyz)
= (7-5+9-8)xyz = 3xyz

(vii) Required sum = 6a³ +(− 4a³) + 10a³ +( −8a³)
=(6-4+10-8)a³ = 4a³

(viii) Required sum = x² − a² + (−5x² + 2a²) +( −4x² + 4a² )
Rearranging and collecting the like terms = x² -5x² -4x² -a² + 2a² +4a²
= (1-5-4)x² +(-1+2+4)a²
= -8x² + 5a²