SOLUTION: Hello. I am struggling with this equation - (2√7+3)(3√7-4) I know that we are supposed to FOIL so when I worked the problem this is what I got 6√7-8√7+9&#87

Algebra ->  Radicals -> SOLUTION: Hello. I am struggling with this equation - (2√7+3)(3√7-4) I know that we are supposed to FOIL so when I worked the problem this is what I got 6√7-8√7+9&#87      Log On


   

Question 301130: Hello. I am struggling with this equation - (2√7+3)(3√7-4) I know that we are supposed to FOIL so when I worked the problem this is what I got 6√7-8√7+9√7-12 cant be the right method because the book says the answer is 30+√7. Can someone tell me what I'm doing wrong? Thanks in advance :)
Found 2 solutions by jim_thompson5910, ankor@dixie-net.com:
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Hint: . In short, %282%2Asqrt%287%29%29%2A%283%2Asqrt%287%29%29=42


Also, -8%2Asqrt%287%29%2B9%2Asqrt%287%29=%28-8%2B9%29%2Asqrt%287%29=1%2Asqrt%287%29=sqrt%287%29 which means -8%2Asqrt%287%29%2B9%2Asqrt%287%29=sqrt%287%29

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
(2√7+3)(3√7-4)
FOIL
6%287%29+-+8sqrt%287%29+%2B+9sqrt%287%29+-+12
:
combine the middle terms
42+-+12+%2B+sqrt%287%29
:
30+%2B+sqrt%287%29