Question

(3x+4)(3x-5) using suitable identites

Answer 1

⭐Solution⭐

➡Given here

(3x+4)(3x-5)=❓

we know,

(a+b)(c+d)=(ac+ad+cb+bd)

so,

use this identity,

Now,

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

= (9x²-15x+12x -20)

= 9x²-3x-20

✔This is Answer ✨

Answer 2

Answer:

9x^2 - 3x - 20

Step-by-step explanation:

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

It is of the form (x+a)(x+b)

(x+a)(x+b) = x^2 + (a+b)x +ab

comparing the RHS of the above and the given,

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

by putting these values in the formula, we get:

(3x)^2 + (4-5)3x + 4(-5)

9x^2 + (-1)3x -20

9x^2 - 3x -20