Start by plugging in 7 in for b in the expression.
So we have 46² + (7) - 5.
Now, PEMDAS tells you to deal with
your exponents before multiplying.
So 46² means 46 · 46 or 2,116.
So we have 2,116 + (7) - 5.
Now add 2,116 + 7 to get 2,123.
Now subtract 5 to get 2,118.