the answer is 54 because if you have 5x+13 and 3x+33 you have to make an equation
70= x+x and x=5x+13 and x=3x+33
and then substitute
x=5(3x+33)+13
x=15x+99+13
move the x over and combine the values
16x=112
Devide
112/16=7
then replace other x to find the next answer
x=3(7)+33
and you get 54
so abd is 70
cbd is 16
and abc is 54
