can someone tell me how 2x3+ 3squared + 2x3squared + 1 is 7+3x3squared? the only part i dont understand is where my book got the 3 from i thought it should be 7+2x3squared?

2. Originally Posted by wonderd
can someone tell me how 2x3+ 3squared + 2x3squared + 1 is 7+3x3squared? the only part i dont understand is where my book got the 3 from i thought it should be 7+2x3squared?
Hi wonderd,

Try using parentheses for multiplication and ^ for taking a value to a power. It would help us tremendously.

$2(3)+3^2+2(3)^2+1 = 7+3(3)^2$

$6+9+18+1=7+27$

$34=34$

3. this is the problem from the book, how do they get the 3?

4. Originally Posted by wonderd
this is the problem from the book, how do they get the 3?
Because $2\sqrt3 + \sqrt3 = (2+1)\sqrt3$

Just like $x + 2x = 3x$

Your question adds $2\sqrt3 to 1\sqrt3 = 3\sqrt3$

5. y is 3sqaured 1?

6. If you have two apples and someone gives you another apple how many do you have?

Now imagine an apple is actually $\sqrt3$

7. can someone explain this differently? bcuz one is not equal to 3 squared

8. All they are doing is pretty much using the FOIL method, first let $x = \sqrt3$

$(\sqrt3 + 1)(2\sqrt3 + 1)$

This can be re written as : $(x + 1)(2x + 1)$ by filling in x's for all square root 3's. now just FOIL that and you will get: $2x^2 + x + 2x + 1$ combine like terms giving you: $2x^2 + 3x + 1$ now fill in $\sqrt3$ for all the x's which gives you $2(\sqrt3)^2 + 3\sqrt3 + 1$ Then once you simplify that, you get $2(3) + 3\sqrt3 + 1 = 7 + 3\sqrt3$