From of plymouth plantation reading warm up b

4a = e , a=e/)

b/4=e , b=)

c+4=e, c=e-)

d-4=e, d=e+)

substitute all values in 5th equation,

a+b+c+d=100  =  e/4 + 4e + e-4+ e+4 =100

  e/4 + 6e = 100

25e = 400

e=16