New Learning Composite Mathematics SK Gupta Anubhuti Gangal Class 7 Algebraic Expression Self Practice 5A Solution
(1) Which of the following algebraic expression are polynomials?
(a) 5 – 7x
(b) y3 + 16y2 – 11
(c) 2y2 – xy + 5/y – 3
(d) 2 – 9/x
(e) 8 – 3x + 4x2 – 6x3
(f) 19
(g) 17z
(h) x + 1/3x – 2
(2) State the numerical coefficient and degree of each monomial
(a) 45
(b) 4x2 /y
(c) 42x-1/4
(d) 9b
(e) 8pq
(f) -12m2n
(g)5/t2
(h) xy2
(i) -7d3
(j) -25x2y
(3) Select the like terms in each polynomial, if any.
(a) 7x – 3x + 8
(b) a + b + 2a – c
(c) a + 3b – c + 5b
(d) 2xy – 5xz + 4yz – yz
(e) mn2 + m2n2 – 2mn2 + 6m2n2
(f) 2ab2 – 7a2b + 9a2b2 + 8a2b
(g) 8(r + s) – 3(r + s) + 5(r – s)
Solution Number 1, 2 & 3:
(4) State the degree of each polynomial
(a) 7 + 3y + y2
(b) 9p3 + 16q2
(c) 8a2b + ab2 – 5ab + 2
(d) 3x3 + 15 + x – 2x2
(e) 0.5x2y + 0.25xy2 + 6x2 + 0.75
(5) Determine whether the given polynomials are monomials, binomials, trinomials or none of these. Then, state the degree and coefficient of the polynomials.
(a) 5c2d
(b) 12x2 + d
(c) 15m2 – 2p + 5
(d) 8x – 5y2 + 11x3
(e) 12ab – 8a2b
(f) -7a3 + 5a2b – ab2 + 10b3
(6) Arrange the given polynomials in order of decreasing degree in x.
(a) 4x + x2 – 8
(b) 8x2 – 3x – 12 + 6x3
(c) x2y – 3y3 + 4x3 – 2xy2
(d) 2x2y – 8xy3 + x3 – y3 + 3xy
(7) Write each polynomial in standard form.
(a) 17 – 3x2 + x + 8x3
(b) 20y3 – 13y – 3y2 + 1
Solution Number 4, 5, 6 & 7:
(8) Evaluate, If a -= 2, b = 1 and c = 10.
(a) c3
(b) (2b)2
(c) (c + b)2
(d) (a – 3)2
(e) (-3c)3
(f) 3a3/b
(g) 9(a2 – b2)
(h) 3b(a3 – c)
(i) a3 + b2 + c)2
(9) Write the algebraic expression for the following situations.
(a) Rita’a age is 4 less than 4 times her daughter’s age x.
(b) The perimeter of an isosceles triangle whose equal sides are of length p cm each and unequal side is q cm.
(d) The speed of a bus is z m/s. Write its speed in km/h.
(e) A pair of shoes cost Rs. x. The cost of a dress is Rs. 200 more than 5 times the cost of the shoes.
Solution Number 8 & 9:
