[tex]a)~~5y\cdot (x+xy-y)=5xy+5xy^{2} -5y^{2} \\\\b)~~x^{4} +3x^{3} +x^{2} -x-(x^{3} -2x^{2} -x)=x^{4} +3x^{3} +x^{2} -x-x^{3} +2x^{2} +x=x^{4} +2x^{3} +3x^{2} \\\\c)~~3x^{2} +2x^{2} =5x^{2} \\\\d)~~2x\cdot (3x+4x^{2} )=6x^{2} +8x^{3} \\\\e)~~(3a)^{2} +4a^{2} =9a^{2} +4a^{2} =13a^{2}[/tex]
Odpowiedź:
Szczegółowe wyjaśnienie:
a) 5y (x+xy-y) =5xy+5xy^2-5y^2
b) x^4 + 3x^3 + x^2-x- (x^3-2x^2-x) =x^4+3x^3+x^2-x-x^3+2x^2+x=x^3+2x^3+3x^2
c) 3x^2+2x^2=5x^2
d) 2x (3x+4x^2) =6x^2+8x^3
e) (3a)^2 + 4a^2=9a^2+4a^2=13a^2
