How do you simplify this? ? do step-by-step, i have the answer i just don’t know how to get to it and i have a test tomorrow

Find the solution of system of equation y= x-4 y=4x+2

Apublic library wants to place 4 magazines and 9 books on each display shelf. the expression 4s+9s represents the total number of items that will be displayed on s shelves. simplify the expression

Oliver read for 450 minutes this month his goal was to read for 10% more minutes next month if all of her medicine go how many minutes will you read all during the next two months