How can I solve this equations ? Y= ai*X + bi where i ranges from 1 to 3

Three sets of variable values :

 a1=[3 2.5 1.7];
 b1=[5.25 3.75 2.125];
 
 a2= [0.875 0.625 0.375];
 b2= [9.5 7.5 4.75];
 
 a3= [0 0 0];
 b3= [13 8.75 6.25];

I want to solve these two equations for different given values of a and b. i=1 to 3.

 Y = ai*X + bi

and,

X0=  (Z- bi*A)/ (1+ ai*A)

Here,

Z= 4.2*(B - 2.5)

where,

if E < 17
  B = 0.4* E 
else 
  B = 0.0158E+8.1
end 
A= 0.3*T

where T is given as

if P<= 29
  T = 9+ 0.04 P  
else 
  T= 11.7 +4.64 log10 P
end

[dpb]

Doesn't make any sense...you could solve the first set for a least squares estimate of slope and intercept (a,b) if the data were the observed X,Y,.

I can't decipher the want for the second part at all, sorry...

Is there some context for the formulation you're trying to describe that might explain from whence this came?