Question

Find the product (4x-9)(4x+5)

Answer 1

Answer:

16x^2-16x-45 is answer.

Step-by-step explanation:

(4x-9)(4x+5)

16x^2+20x-36x-45

16x^2-16x-45

Answer 2

$The \: product \: of \: (4x-9)(4x+5)$

$= [4x + (-9 )]( 4x + 5 )$

/* By algebraic identity */

$\boxed{ \pink{(x+a)(x+b) = x^{2} + (a+b)x+ ab }}$

$= (4x)^{2} + ( -9 + 5 )(4x) + (-9) \times 5$

$= 16x^{2} + (-4)(4x) - 45$

$= 16x^{2} - 16x- 45$

Therefore.,

$\red {The \: product \: of \: (4x-9)(4x+5) }$

$\green {= 16x^{2} - 16x- 45 }$

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