x+490=576
x =576-490
x =86
ai minh minh lai
x + 490 = 578 - 2
x + 490 = 576
x = 576 - 490
x = 86
x+490=578-2
x+490=576
x =576-490
x =86
x+490=578-2
x+490=576
x =576-490
x =86
x + 490 = 578 - 2
x + 490 = 576
x = 576 - 490
x = 86.
x + 490 = 578 - 2
x + 490 = 576
x = 576 - 490
x = 86
x + 490 = 576
x = 576 - 490
x = 86