Given equation is:
[tex]3y^2+(y+7)^2-15[/tex]
let us simplify,
use the formula
[tex](a+b)^2=a^2+2ab+b^2[/tex][tex]\begin{gathered} 3y^2+(y+7)^2-15^{} \\ 3y^2+(y^2+2\cdot7\cdot y+7^2)-15 \\ 3y^2+y^2+14y+49-15 \\ 4y^2+14y+34 \end{gathered}[/tex]
The answer is
[tex]4y^2+14y+34[/tex]
