Sponsor Area

Algebraic Expressions

Question
CBSEENMA7001002

(a) From the sum of 3x − y + 11 and − y − 11, subtract 3x − y − 11.

(b) From the sum of 4 + 3x and 5 − 4x + 2x2, subtract the sum of 3x2 − 5x and − x2 + 2x + 5.

Solution

(a) (3x − y + 11) + (− y − 11)

= 3x − + 11 − y − 11

= 3x − − y + 11 − 11

= 3x − 2y

(3x − 2y) − (3x − − 11)

= 3x − 2y − 3x + + 11

= 3x − 3x − 2y + + 11

= − y + 11

(b) (4 + 3x) + (5 − 4x + 2x2) = 4 + 3x + 5 − 4x + 2x2

= 3x − 4x + 2x2 + 4 + 5

= − x + 2x2 + 9

(3x2 − 5x) + (− x2 + 2x + 5) = 3x2 − 5x − x2 + 2x + 5

= 3x2 − x− 5x + 2x + 5

= 2x2 − 3x + 5

(− x + 2x2 + 9) − (2x2 − 3x + 5)

= − x + 2x2 + 9 − 2x2 + 3x − 5

= − x + 3x + 2x2 − 2x+ 9 − 5

= 2x + 4

Some More Questions From Algebraic Expressions Chapter

(a) Identify terms which contain x and give the coefficient of x.

(i) y2x + y (ii) 13y2− 8yx (iii) x + y + 2

(iv) 5 + zx (v) 1 + x+ xy (vi) 12xy2 + 25

(vii) 7x + xy2

(b) Identify terms which contain y2 and give the coefficient of y2.

(i) 8 − xy2 (ii) 5y2 + 7x (iii) 2x2y −15xy2 + 7y2

Classify into monomials, binomials and trinomials.

(i) 4y − 7z (ii) y2 (iii) x + y − xy

(iv) 100 (v) ab − a − b (vi) 5 − 3t

(vii) 4p2− 4pq2 (viii) 7mn (ix) z2 − 3z + 8

(x) a2 + b2 (xi) z2 + z (xii) 1 + x + x2

Identify like terms in the following:

(a) −xy2, − 4yx2, 8x2, 2xy2, 7y, − 11x2, − 100x, −11yx, 20x2y, −6x2y, 2xy,3x

(b) 10pq, 7p, 8q, − p2q2, − 7qp, − 100q, − 23, 12q2p2, − 5p2, 41, 2405p, 78qp, 13p2qqp2, 701p2

Simplify combining like terms:

(i) 21b − 32 + 7b − 20b

(ii) − z2 + 13z2 − 5z + 7z3 − 15z

(iii) p − (p − q) − q − (− p)

(iv) 3a − 2b − ab − (a − b + ab) + 3ab + b − a

(v) 5x2y − 5x2 + 3y x2 − 3y2 + x− y+ 8xy2 −3y2

(vi) (3 y+ 5y − 4) − (8y − y2 − 4)

Add:

(i) 3mn, − 5mn, 8mn, −4mn

(ii) − 8tz, 3tz − zz − t

(iii) − 7mn + 5, 12mn + 2, 9mn − 8, − 2mn − 3

(iv) a + b − 3, b − a + 3, a − b + 3

(v) 14x + 10y − 12xy − 13, 18 − 7x − 10+ 8xy, 4xy

(vi) 5m − 7n, 3n − 4m + 2, 2m − 3mn − 5

(vii) 4x2y, − 3xy2, − 5xy2, 5x2y

(viii) 3p2q2 − 4pq + 5, − 10p2q2, 15 + 9pq + 7p2q2

(ix) ab − 4a, 4b − ab, 4a − 4b

(x) x− y2 − 1 , y2 − 1 − x2, 1− x2 − y2

Subtract:

(i) − 5yfrom y2

(ii) 6xy from − 12xy

(iii) (a − b) from (b)

(iv) a (b − 5) from b (5 − a)

(v) − m2 + 5mn from 4m2 − 3mn + 8

(vi) − x2 + 10x − 5 from 5x − 10

(vii) 5a2 − 7ab + 5b2 from 3ab − 2a2 −2b2

(viii) 4pq − 5q2 − 3p2 from 5p2 + 3q− pq

(a) What should be added to x2 + xy + y2 to obtain 2x2 + 3xy?

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

What should be taken away from 3x2 − 4y2 + 5xy + 20 to obtain

− x2 − y+ 6xy + 20?

(a) From the sum of 3x − y + 11 and − y − 11, subtract 3x − y − 11.

(b) From the sum of 4 + 3x and 5 − 4x + 2x2, subtract the sum of 3x2 − 5x and − x2 + 2x + 5.