1 câu trả lời
a x 2 + a + a x 4 = 30
=> a x 2 + a x 1 + a x 4 = 30
=> a x (2 + 1 + 4) = 30
=> a x 7 = 30
=> a = 30 : 7
=> a = 30/7
a x 2 + a + a x 4 = 30
=> a x 2 + a x 1 + a x 4 = 30
=> a x (2 + 1 + 4) = 30
=> a x 7 = 30
=> a = 30 : 7
=> a = 30/7