Respuesta :

bantawahenhse

Step-by-step explanation:

solution,

given

DF = 42

DE = 7x+1

EF = 4x-3

DE = ?

here,

or, DF = DE +EF

or, 42 = 7x+1+4x-3

or, 42 = 11x-2

or, 42+2 = 11x

or, 44/11 = x

or, 4 = x

then,

replacing value of x in DE

DE = 7x+1

= 7*4+1

= 28+1

= 29