.
The correct solution is THIS:
30 + (2/9)*x = 100 ====>
(2/9)x = 100-30 = 70 ====> x = = 35*9 = 315 dollars.
Ignore writing by @gosgarithmetic since it is T O T A L L Y W R O N G.
@gosgarithmetic, when, at last, will you leave this forum FOREVER ???