Question 2 - Figure it out - Page 93, 94 - Chapter 4 Class 7 - Expressions using Letter-Numbers (Ganita Prakash)

Transcript

Question 2 (a) Simplify each of the following expressions: (a) p + p + p + p, p + p + p + q, p + q + p – q, Let’s do it one by one p + p + p + p = 4p p + p + p + q = 3p + q p + q + p – q = p + p + q – q = 2p + 0 = 2p Question 2 (b) Simplify each of the following expressions: (b) p – q + p – q, p + q – p + q, Let’s do it one by one p – q + p – q = p + p – q – q = (p + p) – (q + q) = 2p – 2q p + q – p + q = (p – p) + (q + q) = 0 + 2q = 2q Question 2 (c) Simplify each of the following expressions: (c) p + q – (p + q), p – q – p – q Let’s do it one by one p + q – (p + q) = p + q – p – q = (p – p) + (q – q) = 0 + 0 = 0 p – q – p – q = (p – p) – q – q = -0 – (q + q) = –2q Question 2 (d) Simplify each of the following expressions: (d) 2d – d – d – d, 2d – d – d – c, Let’s do it one by one 2d – d – d – d = 2d – (d + d + d) = 2d – 3d = –d 2d – d – d – c = 2d – (d + d) – c = 2d – 2d – c = 0 – c = –c Question 2 (e) Simplify each of the following expressions: (e) 2d – d – (d – c), 2d – (d – d) – c, Let’s do it one by one 2d – d – (d – c) = 2d – d – d + c = 2d – (d + d) + c = 2d – 2d + c = c 2d – (d – d) – c = 2d – d + d – c = 2d – c Question 2 (f) Simplify each of the following expressions: (f) 2d – d – c – cNow, 2d – d – c – c = (2d – d) – (c + c) = d – 2c