Page 100 - Start Up Mathematics_7

Example 4: A. Identify the terms which contain x and also give the coefficient of x.

2
2
(a) 3 + xy + x (b) xy + z x
2
2
B. Identify the terms which contain y and also give the coefficient of y .
2
2
3
(a) 5y + 7x (b) 5x y – 15xy – 2y 2
Solution: A. Expression Terms with x Coefficient of x
xy y
(a) 3 + xy + x
x 1
xy 2 y 2
2
2
(b) y + z x z x z 2
2
B. Expression Terms with y 2 Coefficient of y 2
(a) 5y + 7x 5y 2 5
2
–15xy 2 –15x
2
3
(b) 5x y – 15xy – 2y 2 –2y 2 –2
Example 5: Classify into monomials, binomials and trinomials.
2
(a) 6x + 2 (b) z 3 (c) x + y 2 (d) 7
2
3
2
2
2
(e) z – 3z + 8 (f) xy + yz + zx 2 (g) y + 2y (h) 3ab c
Solution: (a) Binomial (b) Monomial (c) Binomial (d) Monomial
(e) Trinomial (f) Trinomial (g) Binomial (h) Monomial
Example 6: State whether the given pair of terms are like or unlike.
5
(a) 3, 54 (b) 3x, x (c) 7x, 7y
2
2
2
(d) 3xy, 7yx (e) 5x y, 3xy (f) 3abc, –5bca
Solution: (a) Like (b) Like (c) Unlike
(d) Like (e) Unlike (f) Like
Example 7: Identify the like terms in the following:
2
2
2
2
2
2
2
(a) –3xy , 4yx , 8x , 2xy , –11x , –11yx, 2x y, 7x , 2xy
2 2
2 2
2
2
2
(b) 7p, 8q, –p q , –100q, –23, 12q p , –5p , 41, 24p, 3p q, qp , 701p 2
2
2
2
2
2
2
2
Solution: (a) –3xy , 2xy ; 4yx , 2x y ; 8x , –11x , 7x ; –11yx, 2xy
2

2
2 2
2
2 2
(b) 7p, 24p ; 8q, –100q ; –p q , 12q p ; –23, 41 ; –5p , 701p ; 3p q, qp 2
EXERCISE 6.1
1. Write the terms of the following algebraic expressions:
2
3
2
(a) 3x + 2x + 1 (b) a + 3a + 2a + 3
2. Classify the following expressions as monomial, binomial or trinomial:
2
3
2
2
(a) 3x + 1 (b) 2x + 2x + 1 (c) 3x – y 2 (d) a + 3ab(a + b)
3. Find the coefficient of x in the following expressions:
2
2 3
(a) –3x (b) 6xyz + 5 (c) xy z – 3 (d) –3xyz + 1
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