Add. (1/4x^4+3/4x^3+7/8x^2+9)+(-3x^4+1/8x^2-9. Please help, this is like chinese to me. Thank you.

X^4/4 + 3X^3/4 + 7X^2/8 + 9 - 3X^4 + X^2/8 - 9,

LCD = 8:

(2X^4 + 6X^3 + 7X^2 -24X^4 +X^2) / 8,
Combine like-terms:
(-22X^4 + 6X^3 + 8X^2) / 8,
Factor out 2x^2:
(2X^2(-11X^2 + 3X + 4) / 8,
Divide numerator and denominator by 2:
X^2(-11X^2 + 3X + 4) / 4