Question

A x 4 = E

Answer 1

A * 4 = E........A = E / 4
B / 4 = E........B = 4E
C + 4 = E......C = E - 4
D - 4 = E.......D = E + 4

A + B + C + D = 100
(E/4) + (4E) + (E - 4) + (E + 4) = 100
E/4 + 6E = 100 ....multiply by 4
E + 24E = 400
25E = 400
E = 400/25
E = 16 <===