<u>ANSWER </u>

<u>EXPLANATION</u>
We the have the equations,

Multiplying through by negative one gives,

Also

and

Dividing through by 2 gives

Making z the subject gives,

Now we substitute equation (3) into equation (1) and (2)
Equation (3) in to equation (1) gives,

This implies that;


We now put equation (3) in (2) to get,

This implies that



But

So,




Dividing through by negative 9 gives

and


Therefore 
5 + 4x
I think that’s right
A + b +c = 75; where a is the greatest number; b is the middle number; c is the least number;
a = 2 * c;
b = 3 + c;
then, 2 * c + 3 + c + c = 75 => 4 * c = 72 => c = 72 / 4 => c = 18 => a = 2 * 18 => a = 36; b = 3 + 18 => b = 21;