Question

expand (4x-5y) (4x+6y) by formula
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Answer 1

(x+a)(x+b)= x²+(a+b)x+ab

(4x)²+(-5y+6y)4x + (-5y)(6y)

16x²+(y)4x+(-30y²)

16x²+4xy-30y²

Answer 2

Answer:

$(4x - 5y)(4x + 6y) \\ {a}^{2} + {b}^{2} (a - b)( a+ b) \\ (4x) {}^{2} + ( 1y) {}^{2} (4x - 5y)(4x + 6y) \\ - 1xy + 10xy \\ 9 {xy}^{2}$

I hope it will help you......