Exodus 9.16
Septuagint

Kai eneken toutou diethrhqhV, 
ina endeixwmai en soi thn 
iscun mou,
kai opwV diaggelh to onoma mou en pash th gh

New Testament - Romans 9.17

legei gar h grafh tw Faraw oti eiV auto touto exhgeira se: 
opwV endeixwmai en soi thn 
dunamin mou 
kai opwV diaggelh to onoma mou en pash th gh

Septuagint

And for this purpose hast thou been preserved, that I might display in thee my strength, and that my name might be published in all the earth

New Testament

For the scripture saith unto Pharoah, For this very purpose did I raise thee up, that I might show in thee my power, and that my name might be published abroad in all the earth

Masoretic Text

but in very deed for this cause have I made thee to stand, to show thee my power, and that my name may be declared throughout all the earth

Comments:  Paul has replaced “strength” (from Brenton’s Septuagint) with “power.”  However, in the LXX manuscript Codex Alexandrinus, the word is dunamin, as in the NT.  The Hebrew word is koach, which the AV translates sometimes as strength and other times as power.

The significant variation here is that the Greek has “show in thee” where the Hebrew has “show thee” - somewhat different concepts.