How to solve a linear equation by substitution? I've been having a tough time figuring this out. This is how I wrote out the question with substitution.
$$\begin{align}
& I_2 = I_1 + aI_1 (T_2 - T_1) \\
& I_1=100\\
&T_2=35\\
&T_1=-5\\
&a=0.000011
\end{align}$$
My try was $I_2 = 100(1) + 0.000011(100) (35(2)-5(1))$
The answer is $100.044$m but I can't figure out the mechanics of the question.
Thanks in advance for any help

The lower temperature is $-5$ and you dropped a sign plus should not be multiplying $T_2$ by $2$.  The correct calculation is $I_2=100+0.000011\cdot 100 \cdot (35-(-5))=100.044$
