New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 8 Algebraic Expressions Self Practice 5C Solution
(1) Subtract
(a) 2x from 7x
(b) -5a from -2a
(c) 3b2 from -5b2
(d) -2xy from 0
(e) -8cd from 8cd
(f) 3(x + y) from 4(x + y)
(2) Subtract the lower expression from the upper expression.
(a) (7a + 5) – (2a + 1)
(b) (9x2 + 3y2) – (5x2 + y2)
(c) (5ab – 7bc) – (2ab + bc)
(d) (9x2y – 11) – (-2x2y – 5)
(e) (2m3 – 9n2) – (4m3 – 11n2)
(f) (4x2y – 5xy2) – (4x2y – 5xy2)
Solution Number 1 & 2:
(3) Arrange the following in columns and subtract.
(a) 7p + 2q + 5c from 9p + 4q + 7c
(b) 3x2 – 8xy – 9y2 from 3x2 – 8xy – 9y2
(c) 8x2 – 9x + 5 from 4x3 – 3x2 + 7x + 11
(d) -2p3 + 7p2 – 20 + 3p from 0
(e) 4ax2 + 7bx – 9t + 6 from 8ax2 – 2bx + 10t -4
(4) Subtract the following without writing in vertical form.
(a) 2x + 3y from 7x + 9y
(b) -2x – y from 2x + y
(c) – 5m2 + 4mn – n2 from 2m2 + 8mn + 3n2
(d) – 2p3 + 4p2 – 7 – p from 16 – 8p
(e) 4xy – 3x2y + 7xy2 from 27 – 7xy2 + 11xy
(f) The sum of x2 – 2xy + y2 and x2 + 3xy + y2 from x2 – 6xy + 4y2
(g) The sum of 9b2 – 3c2 and 2b2 + bc – 2c2 from the sum of 2b2 – 2bc – c2 and c2 + 2bc – b2
SOLUTION Number 3 & 4:
(5) Simplify:
(a) 3x2 – 5x + 7 – 5x2 – 11 + 8x + 20 + 9x2 – 6x
(b) 5x3 – 8 + 7x2y – 7xy + 10xy2 + 11 – 2x3 – 5x2y + 9xy – 6xy2
(6) The area of a square4x2 – 2xy – 6y2 square units. A triangle inside has an area of -5xy + 4y2 – 3x2 square units. Find the area of the shaded region.
Solution Number 5 & 6:
This is very useful
It is a very good work in students of class 7