Please help I'll make you brainiest

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

The spring the owner of a sporting good store decreases the price of winter gloves from $10 to $8 each increases the price of swimming goggles from $8 to $10 without doing the math you think the percent decrease in the price of the gloves the same as the percent increase of the goggles explain why or why not

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?