To solve the system we multiply the first equation by 2, then we get:
[tex]\begin{gathered} 30q-8r=124 \\ 5q+8t=86 \end{gathered}[/tex]Now we add the equations:
[tex]\begin{gathered} 35q=210 \\ q=\frac{210}{35} \\ q=6 \end{gathered}[/tex]Once we know the value of q we plug it in the first equation and solve for r:
[tex]\begin{gathered} 15(6)-4r=62 \\ 90-4r=62 \\ 28=4r \\ r=\frac{28}{4} \\ r=7 \end{gathered}[/tex]Then q=6 and r=7 and the answer is B.
