The correct answer is:
409
Explanation:
Let x be the number of students who listed instagram as their favorite. "32 fewer than two times" x would be
2x-32
We know that this is the number who preferred the other site, which is 786:
2x-32 = 786
Add 32 to each side:
2x-32+32 = 786+32
2x = 818
Divide both sides by 2:
2x/2 = 818/2
x = 409