He has been very interested in doing research on since he was at high school. a. biology b. biological c. biologist d. biologically

option a is right.biology

biology

Explanation:

This is because research is made on a subject which should basically be a noun but since there's on article before the missing word therefore the noun biology suits best

our founding fathers introduced the revolutionary idea that each person's desire to pursue their idea of happiness was not self-indulgence, but a necessary driver of a prosperous society. they created a government to defend that right for everyone.

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4