Question 284499
Something or other plus 50 is 72?
Then x + 50 = 72
Check it by subtracting fifty from both sides.
x = 22
That's if 50 plus 22 is 72.
It is.

OK, I'll do the other two even though there's only supposed to be one problem per question.

A is greater than or equal to 90% questions correct.

You'd have to write A is greater than or equal to 90 using > with a line under it.

2n plus three is at most five. That means its less than or equal to five.

2n + 3 is < or = 5