Question

a. 2x(3-4) and 4x²-5x
add the following
b. (x²+6x+9)(x²-6x+9)
evalute the following
c. (2x+7)(2x+4)
evalute the following​

Answer 1

Answer:

a) 2x(3-4) + 4x²-5x = 2x(-1) + 4x²-5x = 4x²-7x

b) (x²+6x+9)(x²-6x+9)

(a+b+c)² = a²+b²+c²+2ab+2bc+2ca

= (x²)²+(6x)²+9²+ 2×x²×6x + 2×6x×9 + 2×9×x²

= x^4 + 36x² + 81 + 12x³ + 108x + 18x²

= x^4 + 12x³ + 54x² + 108x + 81

c) (2x+7)(2x+4)

(x+a)(x+b) = x² + x(a+b) + ab

=(2x)² + 2x(7+4) + 7×4

= 4x² + 22x + 28