Answer:
yes its B mark brainliest please
Step-by-step explanation:
IT IS
B
B
B
B
B
The element gold (au) occurs in the 6th period
1.) you would distribute the 6---- 12x-66+15
2.) you would add like terms---- 12x-51=3x+12
3.) you would subtract 3x from each side of the equal sign---- 9x-51=12
4.) you would add 51 on each side of the equal sign----9x=63
5.) you would divide both sides of the equal sign by 9 giving you you answer--------- x=7
$486
18x27=486
Hope this helps :)
