Hmm I’ve done this before but I can’t remember sorry but I will try and think
Answer:
a = - 6
Step-by-step explanation:
Given
f(x) = 3x + 5 , then
f(a) = 3a + 5 and f(a) = - 13 , then equating the right sides
3a + 5 = - 13 ( subtract 5 from both sides )
3a = - 18 ( divide both sides by 3 )
a = - 6
I wanna say 60 but i dont know