[tex]12 {x}^{2} + 8x + 1[/tex]
[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]
[tex](4 {x}^{2} + 6x + 7) - ( - 8 {x}^{2} - 2x + 6) \\ = 4 {x}^{2} + 6x + 7 + 8 {x}^{2} + 2x - 6 \\ = 4 {x}^{2} + 8 {x}^{2} + 6x + 2x + 7 - 6 \\ = 12 {x}^{2} + 8x + 1[/tex]
[tex]\circ \: \: { \underline{ \boxed{ \sf{ \color{green}{Happy\:learning.}}}}}∘[/tex]
