Practice solving more challenging problems involving scientific notation.

Problem

Simplify this expression and write the result in scientific notation.
space, start fraction, 7, dot, 10, start superscript, 5, end superscript, divided by, 2, dot, 10, start superscript, minus, 2, end superscript, times, 2, point, 5, dot, 10, start superscript, 9, end superscript, end fraction