x : 8 + x * 8 - 56,78 = 69,11 9 * 2
<=> x * 1/8 + x * 8 - 56,78 = 138,22
<=> x * ( 1/8 + 8 ) = 195
<=> x = 195 : ( 1/8 + 8 )
<=> x = 24
Vậy x= 24
Học tốt ^.^ !
x:8+x*8-56.78=69.11*2
x:8+x*8-56.78=138.22
x:8+x*8=138.22+56.78
x:8+x*8=195
x*1/8+x*8=195
x*65/8=195
x =195:65.8
x =24