Ijust need someone to check my

what is the sum of the arithmetic sequence 3, 9, if there are 24 terms?

a) 1452
b) 1728 (my answer)
c) 2028
d) 2268

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3

To diagonalize an nxn matrix a means to find an invertible matrix p and a diagonal matrix d such that a pdp d p ap or [1 3 dh epap 3 let a=-3 -5 -3 3 3 1 step 1: find the eigenvalues of matrix a "2's" step 2: find the corresponding eigenvectors of a step 3: createp from eigenvectors in step 2 step 4 create d with matching eigenvalues.