Answer :
s = -3
Explanation :
Using method of substitution by expressing one equation to only one variable.
Equation 1 : 3s + 2t = -4
Equation 2 : -6s - 10t = -7
Express equation 1 as t in terms of s :
[tex]\begin{gathered} 3s+2t=-4 \\ 2t=-3s-4 \\ t=\frac{-3s-4}{2} \end{gathered}[/tex]Substitute t to the equation 2 :
[tex]\begin{gathered} -6s-10t=-7 \\ -6s-10(\frac{-3s-4}{2})=-7 \\ -6s-5(-3s-4)=-7 \\ -6s+15s+20=-7 \\ 9s=-7-20 \\ 9s=-27 \\ s=-\frac{27}{9}=-3 \end{gathered}[/tex]The answer is s = -3
