Respuesta :

bc and ef are congruent so that means
4x-7 =2x+3  subtract 2x from both sides
-2x     -2x
_________
2x-7 = 3       add seven to both sides
   +7  +7
________
2x = 10     divide both sides by 2
__     ___
2       2

x=5   replace x with 5

4(5) -7= 13
2(5) +3=13

both bc and ef equal 13