Someone me make a proof for the bottom question

DB = CA (Proved)

Step-by-step explanation:

Statement 1.

∠D = ∠C, M is the midpoint of DC and ∠1 = ∠2

Reason 1.  

Given

Statement 2.

Between Δ DBM and Δ CAM,  

(i) DM = CM,

(ii) ∠D = ∠C  and  

(iii) ∠DMB = ∠CMA

Reason 2.

(i) given  

(ii) given and  

(iii) ∠ DMB = ∠1 + ∠AMB and  ∠CMA = ∠2 + ∠AMB

Since ∠1 = ∠2, so, ∠DMB = ∠CMA.

Statement 3.

Δ DBM ≅ Δ CAM

Reason 3.

By angle-side-angle rule.

Statement 4.

DB = CA

Reason 4.

Corresponding sides of two congruent triangles. (Answer)

i think the answer is seven, for if i'm being useless °ω°

step-by-step explanation:

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.