Question

a) (5x-8)[2(x+1)+3(x+2)]-(3x-4)[5(x+2)-2(x+3)]
b) (3xy-5)(3xy+50-(3xy-2)²
c) (x+5)(x²-1)-x(x+4)²+(x+1)²
d) (x-3)(x+3)(x²+9)-(x²+2)²+3(x-1)²
rezolvare completa.

Answer 1

(5x-8)[2(x+1) +3(x+2)]-(3x-4)[5(x+2) -2(x+3]
=(5x-8)(5x+8)- (3x-4)(3x+4)
= 25x²-64 - 9x²+16
=16x²- 48


 (3xy-5)(3xy+5) - (3xy-2)²
= 9x²y² - 25 - 9x²y²+12xy- 4
=12xy -29



 (x+5)(x²-1)-x(x+4)² +(x+1)²
= x³ -x+5x²-5-x³- 8x²-16x+x²+2x+1
=  -2x²- 15x - 4



 (x-3)(x+3)(x²+9)-(x²+ 2)²+ 3(x-1)²
= (x²-9)(x²+9)-x⁴-4x²-4+3x²- 6x+3
=x⁴- 81- x⁴-x²-6x -1
= -x² -6x-82