Question

Plese someone answer me b asap

Answer 1

Answer:

$\huge\boxed{\sf 9y^2 -22y-24}$

Step-by-step explanation:

$\sf (3y-1)^2 -(2y+4)^2+(2y-3)(2y+3)\\\\Using \ formula:\\\\1) (a-b)^2 = a^2-2ab+b^2\\\\2) (a+b)^2= a^2+2ab+b^2\\\\3) (a+b)(a-b) = a^2-b^2\\\\Applying \ Formulas\\\\(3y)^2-2(3y)(1)+(1)^2-[(2y)^2+2(2y)(4)+(4)^2]+(2y)^2-(3)^2\\\\9y^2-6y+1-[4y^2+16y+16]+4y^2-9\\\\9y^2-6y+1 -4y^2-16y-16+4y^2-9\\\\Combining \ like \ terms\\\\9y^2-4y^2+4y^2-6y-16y+1-16-9\\\\9y^2 -22y-24\\\\\rule[225]{225}{2}$

Hope this helped!

~AH1807

Answer 2

Answer:

a) $\frac{1}{3}$ k² - 9

b) -7y² - 3

Step-by-step explanation:

a) ($\frac{2}{3}$ k - 6)² - ($\frac{1}{3}$ k + 3)²

  = $\frac{4}{9}$ k² - 36 - $\frac{1}{9}$ k² + 9

  = $\frac{4}{9}$ k² - $\frac{1}{9}$ k² + 9 -36

  = $\frac{3}{9}$ k² - 27

  = $\frac{1}{3}$ k² - 9

____________________________________

b) (3y - 1)² - (2y + 4)² + (2y - 3) (2y + 3)

  = 9y² - 1 - 4y² + 16 + (2y - 3) (2y + 3)

  = 9y² - 4y² - 1 + 16 + (- 3) (4y² + 6y)

  = 5y² + 15 - 12y² - 18

  = 5y² - 12y² + 15 - 18

  = -7y² - 3

Hope this helps!

(NOTE: Do you mind marking me as Brainliest?)