$2x \times \left( {x}^{2}+8x-3 \right)+1\left( {x}^{2}+8x-3 \right)$
Distribute $2x$ through the parentheses$2{x}^{3}+16{x}^{2}-6x+1\left( {x}^{2}+8x-3 \right)$
Any expression multiplied by $1$ remains the same$2{x}^{3}+16{x}^{2}-6x+{x}^{2}+8x-3$
Collect like terms$2{x}^{3}+17{x}^{2}-6x+8x-3$
Collect like terms$2{x}^{3}+17{x}^{2}+2x-3$