Mark the letter A, B, C or D in your answer sheet to indicate the underlined part that needs correction in each of the following questions.

Dams are used to control flooding, provide water for irrigation, and generating electricity for the surrounding area

A. to control flooding

B. irrigation

C. generating

D. surrounding area

﴾15 ‐ x﴿ +﴾ x ‐ 12﴿ = 7 ‐ ﴾‐ 5 + x﴿

15 ‐ x + x ‐ 12 = 7 + 5 ‐ x

15-12-x+x=7+5-x

15 ‐ 12 = 12 ‐ x

12 ‐ x = 3

x = 12 ‐ 3

x = 9