Solve (2x + 3) - (9x - 3)

Timed*** there are 8 rows and 8 columns, or 64 squares on a chessboard. suppose you place 1 penny on row 1 column a, 2 pennies on row 1 column b, 4 pennies on row 1 column c, and so on … how many pennies are on each square? a =   b =   c = d =   e =   f = g =   h =

Im literally having a mental breakdown

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10