Question

4. Willoul dums
(1) (1+3+5+7+9+11+13)
1 (1+3+5+ 7 +9+11+13+15+17 +19+21 +23)
(1) Express 81 as the sum of 9 odd numbers.
(11) Express 100 as the sum of 10 odd numbers.
6. Write a Pythagorean triplet whose smallest member is
(iii) 16
(ii) 14
(vi)
(1) 6
7. Evaluate:
(1) (38)2 – (37)
(ii) (75)2 – (74)2
(iv) (105)2 – (104) (v) (141)2 – (140)
8. Using the formula (a + b)2 = (a? + 2ab + b2), evaluate:
(1) (310)
(ii) (508)2
9. Using the formula (a - b)2 = (a? - 2ab + b2), evaluate:
(1) (196)
(ii) (689)2
10. Evaluate: (1) 69x71 (ii) 94 x 106.
11. Evaluate: (1) 88 x 92 (11) 78 X 82.
solve q no.6 plz​

Answer 1

Step-by-step explanation:

4.Solve without adding

1)1+3+5+7+9+11+13

1+3=4 (square of 2)

4+5=9(square of 3)

9+7=16(square of 4)

16+9=25(square of 5)

25+11=36(square of 6)

36+13=49(square of 7)

2)till 13 same then:

49+15=64(square of 8)

64+17=81(square of 9)

81+19=100(square of 10)

100+21=121(square of 11)

121+23=144(square of 12)

5.1)1+3+5+7+9+11+13+15+17

11)1+3+5+7+9+11+13+15+17+19