Jack's average in math for the first nine weeks was a 90. The second nine weeks his average dropped to a 54. What is the percent decrease in his average from the first nine weeks to the second?

John used linear combination to solve the system of equations shown. he did so by multiplying the first equation by -3 and the second equation by another number to eliminate the x-terms. what number did jonas multiply the second equation by? 4x-6y=23x+5y=11

Find the length of the diagonal of the rectangle. round your answer to the nearest tenth. || | | 8 m | | | | 11 m

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex