Question

Efectuati urmatoarele calcule:
a) (x-2)(x+1)+3x(x-3)-2(x²-3x-4)

b)- $\frac{1}{3}$x²·(-3y)²+0,5x·(-4xy²)-8$x^{4}$$y^{6}$:(-2xy²)²+$\frac{4}{15}$x²:(-$\frac{2}{5}$)·3y²

Answer 1

a) (x-2)(x+1)+3x(x-3)-2(x²-3x-4)=
x²-x-2+3x²-9x-2x²+6x+8=
2x²-4x+6=
2(x²-2x+3)=
2(x-3)(x+1)

b)-1/3x²·(-3y)²+0,5x·(-4xy²)-8x⁴y⁶:(-2xy²)²+4/15x²:(-2/5)·3y²=
-1/3x²·9y²+(-2x²y²)-8x⁴y⁶:4x²y⁴+4/15x²:(-2/5)·3y²=
-3x²y²-2x²y²-2x²y²-2x²y²=
-9x²y²