Step-by-step explanation:
collect the like terms 12x+4=9x+8
12x-9x=8-4
3x=4
X=1.333
Answer:
8
➝12x+4+9x+8=180
➝12x+9x+4+8=180
➝21x+12=180
➝21x=180-12
➝21x=168
➝x=168/21
➝x=8
