How do you solve (2x+y)*(y+4x) ?

Well it's obvious that you don't know the FOIL method so let me teach you it. FOIL stands for First, Outer, Inner, Last. What that means is basically multiply the first number in the first parenthesis and the first variable in the second parenthesis. You do what FOIL tells you to basically. So next you would do the outer numerals and the inner numerals and finally the last numerals and you would have your answer by adding and simplifying whatever comes out. BTW if there is a negative sign it's the same rule as just multiplying and dividing by a negative. 2 negative = positive and 1 negative = negative.