What is sum of the area under the standard normal curve to the left of z = -1 and to the right og z = 1.25?

From standard tables, the area to the left of z = -1 is
A₁ = 0.1587

The area to the left of z = 1.25 is
A₂ = 0.8944
Therefore the area to the right of z = 1.25 is
1 - A₂ = 0.1056

The sum of the areas to the left of z = -1 and to the right of z = 1.25 is
0.1587 + 0.1056 = 0.2643

 0.2643

What exactly is your question?