Q. What is the sum of (4x5−8x3+31x2) and (21x3−4x2)?Choose 1 answer:(A) 4x5−12x3+65x2(B) 4x5−215x3−311x2(C) 4x5−27x3−x2(D) 4x5−217x3+311x2
Write down polynomials: Write down the given polynomials and prepare to combine like terms.We have:First polynomial: 4x5−8x3+(31)x2Second polynomial: (21)x3−4x2To find the sum, we will add the coefficients of the like terms.
Combine x5 terms: Combine the coefficients of the x5 terms.Since there is only one x5 term in the first polynomial and none in the second, the x5 term in the sum is 4x5.
Combine x3 terms: Combine the coefficients of the x3 terms.The first polynomial has −8x3 and the second polynomial has (1/2)x3. Adding these gives us −8x3+(1/2)x3=−8x3+0.5x3=−7.5x3.
Combine x2 terms: Combine the coefficients of the x2 terms.The first polynomial has (1/3)x2 and the second polynomial has −4x2. Adding these gives us (1/3)x2−4x2=(1/3)x2−(12/3)x2=−(11/3)x2.
Write down final sum: Write down the final sum of the polynomials.Combining the results from the previous steps, we get:4x5−7.5x3−(311)x2However, we need to express −7.5x3 as a fraction to match the answer choices. −7.5 is the same as −(215), so the term becomes −(215)x3.
Match with answer choices: Match the final expression with the given answer choices.The final expression is 4x5−(215)x3−(311)x2, which corresponds to answer choice (B).
More problems from Compare linear, exponential, and quadratic growth