in this calculus. formula used,
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode. or KaTeX parse error: KaTeX doesn't work in quirks mode.

Explanation

Here,
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode. _[L.C.M]
KaTeX parse error: KaTeX doesn't work in quirks mode. _{[add square in both side]}
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode. _{[cross multiply]}
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode.

Now,
KaTeX parse error: KaTeX doesn't work in quirks mode.
KaTeX parse error: KaTeX doesn't work in quirks mode. _[L.C.M]
KaTeX parse error: KaTeX doesn't work in quirks mode. [ put the value of KaTeX parse error: KaTeX doesn't work in quirks mode.]
KaTeX parse error: KaTeX doesn't work in quirks mode.
Ans: KaTeX parse error: KaTeX doesn't work in quirks mode.