a) ( 509 + 355 ) : x = 840 : 35
864 : x = 24
x = 864 : 24
x = 36
b) 890 : x = 35 dư 15
=> 890 : x - 15 = 35
=> 890 : x = 35 + 15
=> 890 : x = 50
=> x = 17,8
A) ( 509 + 355 ): x = 840 : 35
= 864 : x = 24
x = 864 : 24
x = 36
B) 890 : x = 35 dư 15
x = 890 : 35
x = 25,428
a) 864 : x = 24
x = 864 : 24
x = 36
b) 890 : x = 35 du 15
=>890 : x - 15 = 35
890 : x = 15 + 35 = 50
x = 890 : 50
x = 17.8
a, \(\left(509+355\right):x=840:35\)
\(\Leftrightarrow864:x=24\)
\(\Leftrightarrow x=36\)
Vậy x = 36
b, \(890:x=35\) dư 15
\(\Rightarrow890=x.35+15\)
\(\Leftrightarrow35x=875\)
\(\Leftrightarrow x=25\)
Vậy x = 25