Câu 1
a, A= 17 x 26 + 26 x 44 + 39 x 26
A= 26 x (17 + 44 + 39)
A= 26 x 100
A= 2600
b,............
Câu 2:
a, 79 x (\(x\) : 23) = 316
\(x\) : 23 = 316 : 79
\(x\) : 23 = 4
\(x\) = 4 x 23
\(x\) = 92
b, 215 - (x : 3) + 14 = 220
215 - (x : 3) = 220 - 14
215 - (x : 3) = 206
x : 3 = 215 - 206
x : 3 = 9
x = 9 x 3
x = 27