Assuming the brackets you have given are two of the sides of the rectangle (I apologise if that's not the case), you just need to multiply the brackets together, which means multiplying each term. Therefore: 2x × x, 2x × 8, 1 × x, and 1 × 8. The answers to these are 2x^2, 16x, x, and 8. Then you just add these terms to get 2x^2 + 17x + 8
