Question

Add the following expressions: 5x – x

2 – 8, 8x2 – 7x – 9 and 3 + 7x2 – 2x.​

Answer 1

$5x - x + (2 - 8) \\ 4x + 2 + 8 \\ 4x + 10$

${8x}^{2} - 7x - 9 + (3 + {7x}^{2} - 2x) \\ {8x}^{2} - 7x - 9 + 3 + {7x}^{2} + 2x \\ {15x}^{2} - 5x - 6$