please, someone explain this to me

Question

int x = 10;
x += 4; // equivalent to x = x + 4
x -= 5; // equivalent to x = x - 5

but the quiz question is
int x =10
x _ = _;

the answer was
int x=10
x/= 5;

Answer 1

x/=5 is equivalent to x = x/5.
Also, x*=5 is equivalent to x = x*5.