16y²-14y -15
1) Let's visualize this to better understand
2) Now let's plug that into the Triangle's area formula:
[tex]\begin{gathered} S=\frac{b\cdot h}{2} \\ S=\frac{(4y-6)(8y+5)}{2} \\ S=\frac{32y^2+20y-48y-30}{2} \\ S=\frac{32y^2-28y-30}{2} \\ S=\frac{32y^2}{2}-\frac{28y}{2}-\frac{30}{2} \\ S=16y^2-14y-15 \end{gathered}[/tex]3) SO the answer is S=16y²-14y -15