a) (2 1/5+1,5):2=
(2,2+1,5):2=3,7:2=1,85
b) 1 1/3 + 1 1/5 : 0,125=
1\frac{1}{3}+1,2:0,125=1\frac{1}{3}+9,6=1\frac{1}{3}+9\frac{6}{10}=1\frac{10}{30}+9\frac{18}{30}=10\frac{28}{30}=10\frac{14}{15}
c) 0,3* 2 1/5 +1 4/5:0,125=
0,3*2,2+1,8:0,125=0,66+14,4=15,06
d) (7,9 - (1 1/2)^2)*5,5=
(7,9-(\frac{5}{2})^2)*5,5=(7,9-\frac{25}{4})*5,5=(7,9-6,25)*5,5=
e)(0,3+3/4): 3 1/2 -15*(1/5){do potęgi 3}=
(0,3+0,75):3,5-15*\frac{1}{125}=
f) 20*(4/5){do potęgi 2}- (4 2/3- 3 11/15): 2,1=
=20*\frac{16}{25}-(\frac{14}{3}-\frac{56}{15}):2,1=\frac{64}{5}-(\frac{70}{15}-\frac{56}{15}):\frac{21}{10}=12\frac{4}{5}-\frac{14}{15}*\frac{10}{21}=12\frac{4}{5}-\frac{4}{9}=
12\frac{36}{45}-\frac{20}{45}=12\frac{16}{45}
g)2 1/2*(0,3)^2 + 2 3/4* (0,1)^2=
2,5*0,09+2,75*0,01=0,225+0,0275=0,2525