Question

the movement of the progress bar may be uneven because questions can be worth more or less (including zero) de
subtract: $left(-2x^{4}-4y^{3}+4z^{3}+6
ight)-left(-9x^{4}-3y^{3}+4z^{3}+9
ight)$
$\bigcirc$ $-7x^{4}+y^{3}+3$
$\bigcirc$ $-11x^{4}-7y^{3}-3$
$\bigcirc$ $-11x^{4}-7y^{3}+8z^{3}+15$
$\bigcirc$ $7x^{4}-y^{3}-3$

Explanation:

Step1: Distribute the negative sign

$(-2x^4 - 4y^3 + 4z^3 + 6) + 9x^4 + 3y^3 - 4z^3 - 9$

Step2: Combine like $x^4$ terms

$-2x^4 + 9x^4 = 7x^4$

Step3: Combine like $y^3$ terms

$-4y^3 + 3y^3 = -y^3$

Step4: Combine like $z^3$ terms

$4z^3 - 4z^3 = 0$

Step5: Combine constant terms

$6 - 9 = -3$

Step6: Combine all simplified terms

$7x^4 - y^3 - 3$

Answer:

$7x^4 - y^3 - 3$ (the fourth option)