Simplify each of the following expressions:
(i) (3 + √3)(2 + √2)
(ii) (3 + √3)(3 - √3)
(iii) (√5 + √2 )2
(iv) (√5 - √2)(√5 + √2)
(i) (3 + √3)(2 + √2) = 3(2 + √2) + √3 (2 + √2)
= 6 + 3√2 + 2√3 + √6
(ii) (3 + √3) (3 - √3) = (3)2 - (√3)2
= 9 - 3 = 6
(iii) (√5 + √2)2 = (√5)2 + (√2)2 + 2(√5)(√2)
= 5 + 2 + 2√10
7 + 2√10
(iv) (√5 - √2)(√5 + √2) = (√5)2 - (√2)2
= 5 - 2 = 3
Length (in hours) | Number of lamps |
|---|---|
300 − 400 | 14 |
400 − 500 | 56 |
500 − 600 | 60 |
600 − 700 | 86 |
700 − 800 | 74 |
800 − 900 | 62 |
900 − 1000 | 48 |
(i) Represent the given information with the help of a histogram.
(ii) How many lamps have a lifetime of more than 700 hours?
Why was Santosh sent to the local school?