Question

add: (-15xz - 4xy) + (20xy - 9yz - 16xz)
options:
16x²y² - 9yz - 31x²z²
5xy - 13yz - 16xz
16xy - 9yz - 31xz
-24xyz
the movement of the progress bar may be uneven because questions can be worth more or less (including zero) depending on your answer.

Explanation:

Step1: Identify like terms

We have two polynomials: \((-15xz - 4xy)\) and \((20xy - 9yz - 16xz)\). The like terms are:

• For \(xy\): \(-4xy\) and \(20xy\)
• For \(xz\): \(-15xz\) and \(-16xz\)
• For \(yz\): \(-9yz\) (only in the second polynomial, so we just take it as is)

Step2: Combine like terms for \(xy\)

\(-4xy + 20xy = 16xy\)

Step3: Combine like terms for \(xz\)

\(-15xz - 16xz = -31xz\)

Step4: Combine like terms for \(yz\)

We have \(-9yz\) (from the second polynomial, no other \(yz\) term to combine with)

Step5: Write the combined polynomial

Putting it all together, we get \(16xy - 9yz - 31xz\) (we can also write it as \(16xy - 31xz - 9yz\) since addition is commutative)

Answer:

\(16xy - 9yz - 31xz\) (which corresponds to the option "16xy - 9yz - 31xz")