first convert expression into 3 address code and then assign each variableb to separate new variable.
in static single assignment form each variable is assigned to another variable.
3 address code for above expression is
t1=d*4
t2=b/9
t3=a+t2
t4=t3+c
t5=t4-t1
t6=t5+e
STATIC SINGLE ASSIGNMENT FORM IS
p1=d*4
p2=b/9
p3=a+p21
p4=p31+c
p5=p41-p11
p6=p51+e
so total 11 variables are required in ssa