Answer :
The solution is
[tex]\begin{gathered} s=\frac{a+b+c}{2} \\ 2s=a+b+c\text{ (cross multiplying)} \\ 2s-b-c=a\text{ } \\ a=2s-b-c \end{gathered}[/tex]a=2s-b
The solution is
[tex]\begin{gathered} s=\frac{a+b+c}{2} \\ 2s=a+b+c\text{ (cross multiplying)} \\ 2s-b-c=a\text{ } \\ a=2s-b-c \end{gathered}[/tex]a=2s-b