Uh oh! Wolfram|Alpha doesn't run without JavaScript.
Please enable JavaScript. If you don't know how, you can find instructions
here
.
Once you've done that, refresh this page to start using Wolfram|Alpha.
k
0
1
-
t
*
l
+
t
*
r
+
t
*
1
-
t
*
a
*
1
-
t
+
b
*
t
d
t
Math Input
Natural Language
Math Input