To solve for the system of equations, I will write the equation down as I rewrite the written form.
a number, n, (n) is added to 15 less than 3 times itself (+3n -15). The result is (=) 101. (101)
Now let's write only what's in the parenthesis.
n + 3n -15 = 101.
The correctly written form in your answers is:
3n - 15 + n = 101, your first answer.