the following is a selected video from your teacher comm where you can browse over 450 complete math lessons with example videos interactive practice problems self tests and more try a complete lesson today at your teacher comm notice that we have two terms inside each set of parentheses here so to multiply the two parts of the problem together we use the foil method the product of the first term 7 times 2 is 14 the product of the outer terms 7 times negative 3 root 5 is negative 21 root 5 the product of the inner terms positive 4 and 5 times 2 is positive 8 root 5 and the product of the last term's positive 4 or 5 times negative 3 root 5 is negative 12 root 25 notice the wind filing we multiply the numbers that are outside the radicals together and the numbers that are inside the radicals together in your next step notice that our middle terms have like radicands and can therefore be combined negative 21 root 5 plus 8 root 5 is negative 13 root 5 bring down the 14 and the square root of 25 is 5 so we have negative 12 times 5 which is negative 60 finally combine 14 minus 60 to get negative 46 minus 13 root 5