It is no answer, because when you get 12x + 48 = 48 + 12x, they cancel each other out.
Angle QRT is an exterior angle to the triangle. The rule is that the exterior angle of a triangle is equal to the sum of its remote interior angles. Those remote interior angles are angle RTS and angle TSR. So our equation is

. We can remove the parenthesis and simplify by combining like terms to get 9x = 5x + 9 + x and 9x = 6x + 9 and 3x = 9. That means that x = 3.
5/6 of a number cannot be greater than the number
Let's translate it into an equation and then solve...
7/x = 7.35
x * 7/x = 7.35 * x
7 = 7.35x
7/7.35 = x
.9524 = x
So 7 divided by .9524 (rounded to the nearest ten thousandth) equals 7.35
So the function is

the intial value is where x=0
where x=0, the value of f(0)=3
grouth is 1/3 but it is decay, so it might be correct, or not because it is decay
it is exponential decay
true it is a stretch of the funciton f(x)=(1/3)^x
when x=3, then f(3)=1/9
the true things are
The function shows exponential decay.
The function is a stretch of the function f(x) = (1/3)x .