Odpowiedź :
1.
a) 3x + 5x - 3x = 5x
b) -2y - 5y + 2y = -5y
c) z + z + z - z - z = z
d) ½ m - 0,5m + ⅛ m - 0,25m = 1/8m - 1/4m = 1/8m - 2/8m = -1/8m
e) 5b - 1/5b - 4/5b + b = 5b
f) -a + a + a - a = 0
2.
a) -2a + b - a - 2b + 3a = -3a - b + 3a = - b
b) -ab + b² + 3ab - 2ab = b² + 3ab - 3ab = b²
c) 2/3x + ⅓ + 2⅓ x + ⅓y = 3x + 1/3 + 1/3y
d) 15xy - 4x + 8y - 6xy + 5x - xy = 8xy + x + 8y
e) 0,2x² - 2y + 1,8x² + 4,3y - x = 2x² + 2,3y - x
f) -¼ + 1/8n - 1/8m + 0,375 = 1/8n - 1/8m = 0,375 - 0,250 = 1/8n - 1/8m + 0,125
3.
a) 3/5m² + 2/3n² + 6 -1/3m² - 2/3n² - 2 3/5 = 9/15m² + 6 - 5/15m² - 2 i 3/5 = 4/15m² + 3 i 2/5
b) 0,5xy² - 1,2y² + 5 - 0,8y² - 2,5xy² - 2 1/8 = -2xy² - 2y² + 2 i 7/8
4.
d1 = a cm
d2 = b dm = 10b cm
P = 1/2 * d1 * d2 = 1/2 * a * 10b = 5ab cm²
[tex]zad.1.\\\ a)3x+5x-3x=8x-3x=5x\\\ b)-2y-5y+2y=-7y+2y=-5y\\\ c)z+z+z-z-z=3z-2z=z\\\ d)\frac{1}{2}m-0.5m+\frac{1}{8}m-0.25m=\frac{1}{8}m-\frac{1}{4}m=-\frac{1}{8}m\\\ e)5b-\frac{1}{5}b-\frac{4}{5}b+b=5b-b+b=5b\\\ f)-a+a+a-a=0+0=0[/tex]
[tex]zad.2.\\\ a)-2a+b-a-2b+3a=0a-b=-b\\\ b)ab+b^2+3ab-2ab=2ab+b^2=b(2a+b)\\\ c)\frac{2}{3}x+\frac{1}{3}+2\frac{1}{3}x+\frac{1}{3}y=3x+\frac{1}{3}+\frac{1}{3}y=\frac{1}{3}(9x+1+y)\\\ d)15xy-4x+8y-6xy+5x-xy=8xy+x+8y\\\ e)0.2x^2-2y+1.8x^2+4.3y-x=2x^2+2.3y-x\\\ f)-\frac{1}{4}+\frac{1}{8}n-\frac{1}{8}m+0.375=\frac{1}{8}n-\frac{1}{8}m+\frac{1}{8}=\frac{1}{8}(n-m+1)[/tex]
[tex]zad.3.\\\ a)(\frac{3}{5}m^2+\frac{2}{3}n^2+6)+(-\frac{1}{3}m^2-\frac{2}{3}n^2-2\frac{3}{5})=\\\ \\\ \frac{3}{5}m^2+\frac{2}{3}n^2+6-\frac{1}{3}m^2-\frac{2}{3}n^2-2\frac{3}{5}=\frac{4}{15}m^2+3\frac{2}{5}\\\ \\\ \\\ b)(0.5xy^2-1.2y^2+5)+(-0.8y^2-2.5xy^2-2\frac{1}{8})=\\\ 0.5xy^2-1.2y^2+5-0.8y^2-2.5xy^2-2\frac{1}{8}=-2xy^2-2y^2+4\frac{7}{8}=\\\ -2y(xy-y)+4\frac{7}{8} [/tex]
[tex]zad.4.\\\ p=a\ cm\\\ q=b\ dm=10b\ cm\\\ \\\ P=\frac{p*q}{2}=\frac{(a\ cm)*(10b\ cm)}{2}=\frac{10ab\ cm^2}{2}=5ab\ cm^2[/tex]