Francesca tried to evaluate an expression. Here is her work: 3(5)2–18÷3
=
3(25)–18÷3 Step 1
=
75–18÷3 Step 2
=
57÷3 Step 3
=
19 Step 4
Is Francesca's work correct?

geometry: triangles

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call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584

the answer is c hope this

answer: i ! the answer is   9000 seconds, also d

hope i

-lavira : )