DIRECT VARIATION F1

x is directly proportional to y. x=12 while y=4. Find y when x is 93.

 

Solution

 

x ⍺ y

x = ky

 

12 = k x 4

 

12 = 4k

4      4

 

k = 3

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

 

k = 3, y= ? x = 93.

 

93 = 3 x y

93 = 3y

3      3

 

y = 31.

 

TRY THIS…………….

 

x is directly proportional to y. x=20 while y=5. Find y when x is 100.

 

Ans. y=25 

FACTORIZE F1

Factorize 144x² - 169y²

 

Solution

 

we use difference of two squares a² – b² = (a - b)(a + b)

 

144x²- 169y²  = 12²x² - 13²y²

 

                   = (12x)² - (13y)²

 

                   = (12x - 13y)( 12x + 13y)

 

Hence 144x² - 169y² = (12x - 13y)(12x + 13y)

 

TRY THIS………………………….

 

Factorize 196e²- 49f²