câu 1:
3.(x+2) + 5x = 22
=> 3x + 6 + 5x = 22
=> 8x = 22 - 6 = 16
=> x = 16/8 = 2
câu 2:
2(x + 1) + 5(x + 2) = 61
=> 2x + 2 + 5x + 10 = 61
=> 7x + 12 = 61
=>7x = 61 - 12 = 49
=> x = 49/7 = 7
hok tốt
# kiseki no enzeru #
C1:
3( x + 2 ) + 5x = 22
3x + 6 + 5x = 22
3x + 5x = 22 - 6
8x = 16
x = 16 : 8
x = 2
C2:
2( x + 1 ) + 5( x +2 ) = 61
2x + 2 + 5x + 10 = 61
2x + 5x = 61 - 2 - 10
7x = 49
x = 49 : 7
x = 7
~ Hok tốt ~