Find the sum of $2 x^2+5 x+7$ and $-10 x^2-7 x+1$.
We are given two polynomials, \(p_1(x) = 2x^2 + 5x + 7\) and \(p_2(x) = -10x^2 - 7x + 1\). The objective is to compute the sum of these two polynomials, \(S(x) = p_1(x) + p_2(x)\). Polynomial addition is performed by combining the coefficients of like terms—that is, terms with the same exponent of \(x\). We have terms with \(x^2\), terms with \(x^1\), and constant terms (terms with \(x^0\)).
To find the sum \(S(x) = (2x^2 + 5x + 7) + (-10x^2 - 7x + 1)\), we group the coefficients of the corresponding powers of \(x\):
\[S(x) = (2x^2 - 10x^2) + (5x - 7x) + (7 + 1).\]
Now, we perform the addition of the coefficients:
Combining these, we obtain the resulting polynomial: \(S(x) = -8x^2 - 2x + 8\).
The resulting polynomial after adding the two given expressions is \(S(x) = -8x^2 - 2x + 8\). Therefore, the sum is \(\boxed{-8x^2 - 2x + 8}\).
Polynomial addition is frequently used in fields like physics and engineering when modeling the resultant force or displacement of an object. For instance, if you are modeling the trajectory of a projectile where one polynomial represents the horizontal position over time and another represents the atmospheric drift, you can find the actual position by adding the two polynomial expressions together. This foundational algebraic skill allows for the simplification of complex systems by combining simple, manageable components into a single representative model.