Question

19. Efectuaţi înmulţirile: a) 2X-(X²-7X-3); c) (3X³ – X² + X).(-5X³); e) -0,5x² (-2X²-3X + 4); g) 3XY-(X²-2XY+Y²); 1) 2,5X²Y (4X² -2XY+0,2Y²); 10X²Y² (6,3) X³Y−3Y² −0,7X; anonică polinomul: b) -4X² (5X²-3X-2); d) (Y² - 2,4Y+6)-1,5Y; f) (-3Y² +0,6Y) (-1,5Y³); ·h) -X²Y (X²Y²-X² -Y²); j) (-2XY² +3XY-X²).(-X²Y²); 1) −1,4X²Y6 (5X³Y-1,5XY²-2Y​

Answer 1

Răspuns:

a) 2X-(X²-7X-3) = 2X-X²+7X+3 = -X²+9X+3

c) (3X³ – X² + X).(-5X³) = -15X⁶+5X⁵-5X³

e) -0,5x² (-2X²-3X + 4) = 0.5X²(2X²+3X-4) = -X³-1.5X²+2X

g) 3XY-(X²-2XY+Y²) = 3XY-X²+2XY-Y² = XY(3-X+2-Y)

h) -X²Y (X²Y²-X² -Y²) = -X²Y(X²Y²-X²-Y²) = -X²Y(X²(Y²-1)-Y²) = -X²Y(X²-1)(Y²-1)

j) (-2XY² +3XY-X²).(-X²Y²) = 2X³Y³-3X²Y²+X³

−1,4X²Y6 (5X³Y-1,5XY²-2Y = -7X⁵Y⁶+2.1X⁴Y⁵-2.8X²Y⁶