Sunday, 23 November 2014

EXPONENTIALS-1




If (x3)(y2) = 500; find x and y.

solution

(x3)(y2) = 500  [500=2x2x5x5x5 by prime factorization].

(x3)(y2) = (53 )x (22)     [ since 500=53 x 23].

equating equal powers,

(x3) = (53)   

x   =   5

also,

(y2) = (22)

 y    =   2

x   =   5 and y    =   2

TRY THIS…………

If (m3)(n5) = 4000; find m and n.

MATRIX 1




Monday, 13 October 2014

PROBABILITY 2


Given the interval of 1-12 inclusive, Find the probability of having an even number or a prime number.

Solution

This is a non-mutually exclusive event.
n(S) = number of sample space = 12

Let P(E)= probability of even numbers = 6/12
Let P(R)= probability of prime  numbers = 5/12
P(EnR) = probability of having both even and prime numbers= 1/12

P(EuR) = P(E) + P(R)  - P(EnR).

 P(EuR) =  6  +  51
                12    12   12

P(EuR) =  11  -   1 
                12     12  

P(EuR) =  10 
                12      

Hence probability of an even number or a prime number is 5/6.

TRY THIS........


Given the interval of 1-15 inclusive, find the probability of having an even number or a prime number.

EXPONENTS 2


Simplify 5
            125-2/3

Solution

5
  125-2/3

=  5 x 1
         125-2/3

=  5 x 1252/3        [Since 1/a-n = an]

=  5 x (1251/3)2        [Since 1251/3 = cube root of 125 = 5]

=  5 x (5)2        

=  5 x 25

= 125        
         
Hence   5        = 125
            125-2/3

TRY THIS…………………………

simplify 5

             27-2/3

DEGREES TO RADIAN


Change 12000 into radians.

Solution     

s = ∏Ó¨/180
            
s = ∏ x 1200
              180

s =  20 radians
        3

Hence 5000 = 20 radians            .
                           3                               

TRY THIS…………….


Change 15000 into radians

ALGEBRA 4


Expand 2x(6x – 5)

Solution

= 2x(6x – 5)

= (2x x 6x) – (2x x 5)

= 12x2 – 10x

Hence 2x(6x – 5) = 12x2 – 10x

TRY THIS……………


Expand 11a(7a – 4)

EXPONENTS 1


Simplify (m4)7

solution

= (m4)7

=  m4x7

=  m28

TRY THIS........


Simplify  (h18)5

ARITHMETICS 2


Evaluate  20 + 6 – 5 – 7 – 9 + 10.

Solution

= 20 + 6 – 5 – 7 – 9 + 10

= 20 + 6 + 10 – 5 – 7 – 9

= 20 + 6 + 10 – ( 5 + 7 + 9)

= 36 – 21

= 15

TRY THIS


Evaluate  35 + 6 – 4 – 7 – 11 + 8

ARITHMETICS 1

Evaluate 144 x 545 + 455 x 144

Solution

= 144 x 545 + 455 x 144

= 144 x (545 + 455)

= 144 x 1000

= 144000

Hence 144 x 545 + 455 x 144 = 144000

TRY THIS............


Evaluate 132 x 376 + 624 x 132

FACTORIZATION 7


Factorize 3x2 - 8x - 35.

Solution

= 3x2 - 8x - 35. We split the middle term (-8x) to be (+7x-15x).

= 3x2 + 7x - 15x - 35.

= (3x2 + 7x) – (15x – 35).

= x(3x + 7) – 5(3x + 7).

= (x - 5) (3x + 7)

Hence 3x2 - 8x – 35 = (x - 5) (3x + 7) answer.


TRY THIS…..


2x2 - x + 15.