CLASS 8 EXPONENTS AND POWERS. ALGEBRAIC EXPRESSIONS AND IDENTITIES - REVISION

CLASS 8

EXPONENTS AND POWERS 

ALGEBRAIC EXPRESSIONS AND IDENTITIES

REVISION


 1. Evaluate:


(i) 6-2 (ii) (-2)-3(iii) (3/4)-2  



2.  Simplify and express the result in power notation with positive exponent:

 

(i) -(3)4×(5/3)4 


(ii) (3-7÷3-10)×3-5  

 

3. Find the value of :

 

(i) (1/2)-2+(1/3)-2+(1/4)-2

 

(ii) {(-2/3)-2}2 



4. Evaluate


(i) (8-1×53)/2-4


(ii) (5-1×2-2)×6-1


5. Find the value of m for which 5m ÷ 5-3 = 55





6. Express the following numbers in standard form.


(i) 0.000000000012085


(ii) 0.00000000008467

 

(Iii) 31860000000


7. Express the following numbers in usual form.

 

(i) 7×10-8 


(ii) 1.0001×109


(iii)  6.7×1012


(iv) 3.5472×106




8. In a stack there are 5 books each of thickness 20 mm and 5 paper sheets each of thickness 0.016 mm. What is the total thickness of the stack?


9.  Identify the terms, their coefficients for each of the following expressions. 


(i) 5xyz2 – 3zy  


(ii) 4x2y2 – 4x2y2z2 + z2



(iii) (x/2) + (y/2) – xy


 (vi) 0.3a – 0.6ab + 0.5b



 10. Classify the following polynomials as monomials, binomials, trinomials. 


(i)  y + 2


(ii) 1057


(iii) 3x +5x2 + x3  


(iv)  7 + y + 5x


(v) 2y – 3y2 + 4y3 


(vi) – 15z2

 


(vii)  ab + bc 


(viii) p2q + pq2

 

11.  Add the following.


(i) ab – bc, bc – ca, ca – ab

 

(ii) 2p2q2 – 3pq + 4, 5 + 7pq – 3p2q2



(iii) l2 + m2, m2 + n2, n2 + l2, 2lm + 2mn + 2nl


 

12.  (i) Subtract 4a – 8ab + 3b + 16 from 11a – 6ab + 5b + 7


(ii) Subtract 3xy + 15yz – 27zx from 5xy – 21yz – 12zx + 30xyz


13.. Find the product of the following pairs of monomials.

 

(i)  4p3, – 3p


(ii) 14p, 0


14. Obtain the volume of rectangular boxes with the following length, breadth and height respectively.


(i) 5a, 3a2, 7a4

 

(ii) xy, 2x2y, 2xy2


15. Obtain the product of

 

(i) 2, 4y, 8y2 , 16y3


(ii) a,2b, 3c, 6abc


16. (a) Simplify 3x (4x – 3) + 5 and find its values for (i) x = 2 (ii) x =1/3


(b) Simplify a (a2+ a + 2) + 6 and find its value for (i) a = 0, (ii) a = 2 (iii) a = – 3.

 


17. (i) Add: 3x (z – x – y) and 2y (z – y – x) 


(ii) Subtract: 3l (l – 4 m + 5 n) from 2l ( 10 n – 3 m + 2 l ) 


 

18. Multiply the binomials.


(i) (3x + 5) and (2x – 3)

 

(ii) (1/4 a2 + 6b2) and 4( a2 – 2/3 b2)
















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