Question

Use suitable identities to find the product of ( 3x-8) ( 3x+ 10)

Answer 1

This as a similar Question

(iii) (3x + 4) (3x - 5)

\bf{Using\: identity} : (x + a) (x + b) = x² + (a+b)x + ab

Here,

x = 3x , a = 4 , b = (-5)

=> (3x)² + { 4 + (-5) }*3x + 4*(-5)

=> 9x² + (4 - 5)*3x - 20

=> 9x² + (-1)*3x - 20

=> 9x² - 3x - 20

Answer 2

Answer:

=9x^2+54x+80

Step-by-step explanation:

Identity to be used: (x + a) (x + b) = x² + (a+b)x + ab

(3x-8)(3x+10)

=(3x)^2+(18)3x+80

=9x^2+54x+80

Hope this helps............

:)