Tìm x biết rằng

a,-7.(5-x)-2.(x-10)=15

b, 3.( x - 4 ) - ( 8 - x ) =12

c,-7 . ( 3x - 5 ) + 2 . ( 7x - 14 ) = 28 

d, 5.( 3 - 2x ) + 5 . (x - 4 ) = 6 - 4x

e, 4. ( x - 5 ) - 3 . ( x + 7 ) = 5. ( - 4 )