Please help me with pre algebra I’ll give brainlist

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

Which statement is true about a number and its additive inverse? a. their product is always one. b. their sum is always one. c. they are always reciprocals of each other. d. their sum is always zero.

As a salesperson you get $50/day and $3.60/each sales you make.if you want to make $60 in one day, how many sales would you need need to make ? a 3b 4c 5d 6 show work.