You would simply plug in the values given into the equation. So for the first one, you would substitute 2 for every x. 7(2)+3(2)+5 =25 same pattern for the other two
I’m not sure but I think it’s sample x
A = ¹/₂bh
A = ¹/₂(32.5)(12.5)
A = ¹/₂(406.25)
A = 203.125 y²
78 is the correct answer.