Answer
Appendix A - Practice : 7 (Answer)
$(7x^{4} - 8x^{2} + x) - (9x^{4} + x^{2} - 18)$
$= -2x^{4} - 9x^{2} + x + 18$
Work Step by Step
Appendix A - Practice : 7 (Solution)
$(7x^{4} - 8x^{2} + x) - (9x^{4} + x^{2} - 18)$
$= 7x^{4} - 9x^{4} - 8x^{2} - x^{2} + x + 18$ (Change signs and group like terms)
$= -2x^{4} - 9x^{2} + x + 18$ (Combine like terms)