For all numbers c and d, let [] be defined by the following equation
c [] d = d^2 +cd - c
if 3 [] g = 25, what is the positive value of g?

Question

anonymous · Answer

g=4

anonymous · Answer

why?

anonymous · Answer

really?

anonymous · Answer

i guess because where you see a "c"you put 3 and where you see d you put g

anonymous · Answer

$$3[]g=g^2+3g-3=25$$

myininaya · Answer

(g+7)(g-4)=0
g=-7, g=4
g=4 is the only positive solution

anonymous · Answer

$$g^2+3g-28=0$$
$$(g-4)(g+7)=0$$
$$g=4$$ or 
$$g=-7$$

anonymous · Answer

had to beat me didn't you but doesn't count because you didn't use latex nyah nyah

myininaya · Answer

yes it does
its readable so it counts

anonymous · Answer

Lol thank you guys for explaining.

myininaya · Answer

satellite did all the explaining

anonymous · Answer

ok you win.  now get some sleep. i mean i am going to get some sleep .  really.  now.