

The answer is either B, and you forgot to put in the ^2 in the answer choice, or C, and you forgot to put an x where there is a _ in the question.
Check the actual question (the one you recieved, not the one posted here) and see where the mistakes are. If f(x) = 8x - 4x - x^3, then your answer is C. However, if B is actually -x^3 + x^2 + 3x - 1, then the answer is B.
9514 1404 393
Answer:
A. 3×3
B. [0, 1, 5]
C. (rows, columns) = (# equations, # variables) for matrix A; vector x remains unchanged; vector b has a row for each equation.
Step-by-step explanation:
A. The matrix A has a row for each equation and a column for each variable. The entries in each column of a given row are the coefficients of the corresponding variable in the equation the row represents. If the variable is missing, its coefficient is zero.
This system of equations has 3 equations in 3 variables, so matrix A has dimensions ...
A dimensions = (rows, columns) = (# equations, # variables) = (3, 3)
Matrix A is 3×3.
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B. The second row of A represents the second equation:

The coefficients of the variables are 0, 1, 5. These are the entries in row 2 of matrix A.
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C. As stated in part A, the size of matrix A will match the number of equations and variables in the system. If the number of variables remains the same, the number of rows of A (and b) will reflect the number of equations. (The number of columns of A (and rows of x) will reflect the number of variables.)
Answer:
x = 25
Step-by-step explanation:
Given
x - 5 = 20 ( isolate x by adding 5 to both sides )
x = 25
120 degrees or 0.67 radians