Question

find the angle which is 4 times its supplement.

Answer 1

Let the angle be x
A/q,
       x = 4(180-x)
   ⇒ x = 720 - 4x
   ⇒ x + 4x = 720
   ⇒ x =720/5
   ⇒ x = 144

So, the angle is 144°

Answer 2

$\huge\star\bold\red{Hello!}$

$\small\sf{Let\:angle\:be\:x}$

$\large\mathtt{A/Q,}$

$\longrightarrow$$\small\sf{x=4(180-x)}$

$\longrightarrow$$\small\sf{x=720-4x}$

$\longrightarrow$$\small\sf{x+4x=720}$

$\longrightarrow$$\small\sf{x=720/5}$

$\longrightarrow$$\small\sf{x=144°}$