Răspuns :
= [ 30 : ( 24 - a) +20 ]= 7 x 5
= [ 30 : ( 24 - a ) +20 ] = 35
= 30 : ( 24 - a) = 35 - 20
= 30 : ( 24 - a) =15
= ( 24 - a) = 30 :15
= ( 24 - a ) = 2
24 - a = 2
a = 24 - 2
a = 22.
= [ 30 : ( 24 - a ) +20 ] = 35
= 30 : ( 24 - a) = 35 - 20
= 30 : ( 24 - a) =15
= ( 24 - a) = 30 :15
= ( 24 - a ) = 2
24 - a = 2
a = 24 - 2
a = 22.