\(b,\frac{26}{30}:\frac{23}{15}\)
\(=\frac{26}{30}\times\frac{15}{23}\)
\(=\frac{26\times15}{30\times23}\)
\(=\frac{390}{690}\)
\(=\frac{13}{23}\)
\(a,\frac{19}{21}+\frac{14}{39}\)
\(=\frac{741}{819}+\frac{294}{819}\)
\(=\frac{1035}{819}\)
\(=\frac{115}{91}\)
a. 19/21 + 14/39 =115/91
b. 26/30 : 23/15 = 13/23
\(\frac{19}{21}+\frac{14}{39}=\frac{115}{91}=1\frac{24}{91}\)
\(\frac{26}{30}:\frac{25}{15}=\frac{13}{23}\)
k mình nha
a,\(\frac{19}{21}+\frac{14}{39}=\frac{1035}{819}\)
b,\(\frac{26}{30}:\frac{23}{15}=\frac{13}{15}:\frac{23}{15}=\frac{13x15}{15x23}=\frac{195}{345}\)
a) 19/21 + 14/39
19/21 = 19x13/21x13 = 247/273
14/39 = 14x7/39x7 = 98/273
247/273+98/273 = 247+98/273 = 345/273
19/21+14/39=345/273
b) 26/30 : 23/15
= 26/30 x 15/23 = 390/690 = 13/23
= 26/30 : 23/15 = 13/23
