Question

If a*b= a^2-b^2/a+b, what is 3*2.

Answer 1

-5
-2
1
2
5

Answer 2

I got 1

Answer 3

So this expression is defining a new operation: *

a*b is defined to be (a^2 - b^2)/(a+b)

is that the right placement of brackets?

Answer 4

Yes

Answer 5

Is my answer 1, right?

Answer 6

Well, notice that
\[ a^2 - b^2 = (a-b)(a+b) \]
Hence
\[ \frac{a^2-b^2}{a+b} = \frac{(a+b)(a-b)}{a+b} = a-b \]
Thus
3*2 = 3 - 2 = 1,
which is what you wrote above.

Answer 7

So when you get problems like this, you are basically plugging in the values into where the c and f notations?

Answer 8

like you plug in the numbers where they are supposed to go? its that easy?

Answer 9

Yes. But it's worth looking at the expression to see if you can simplify it first, as I did above.

Answer 10

Do u mind looking at this one?

Answer 11

post as a new question if you don't mind.

Answer 12

Let r (triangle) s=rs + s for all integers r and s. What is the value of 4 (triangle) 5?

Answer 13

@JamesJ

Answer 14

options:

18
20
24
25
40

Answer 15

what do you think it is?

Answer 16

I got 25:)?

Answer 17

yes

Answer 18

ok cool

Answer 19

I'll post more if I have to in a sec!