crosbylotus crosbylotus 17-11-2022 Mathematics contestada What is the first step in evaluating this expression? -_- school be wild- 15 + 20 ÷ ( 10 − 7 ) + 12 A. Subtract 7 from 10. B. Divide 20 by 10. C. Add 15 and 20. D. Add 7 and 12.