Verified answer

25 - 9*z^2

= 5^2 - (3*z)^2

= (5 - 3*z)*(5 + 3*z) <<<

Difference of sSquares: A² - B² = (A + B)(A - B)

25 - 9z² = (5)² - (3z)² = (5 + 3z)(5 - 3z)

a² - b² ≡ (a - b)(a + b)

=> 25 - 9z² = 5² - (3z)² = (5 - 3z)(5 + 3z)

:)>

distinction of two suited squares: a^2-b^2= (a+b)(a-b) change: 16x^4-121y^4 locate a and b: a^2=16x^4 a=4x^2 b^2=121y^4 b=11y^2 Plug a and b lower back into equation: 16x^4-121y^4=(4x^2+11y^2)(4x^2-11y^2)

(5+3z)(5-3z)