After substituting, what is the first step when evaluating x+3x-4.2 when x= 5?
a. multiply 3 by 5
b. add 5 and 3
c. subtract 4.2 from 5
d. add 3 and 4.2.

After substitution, the first step when evaluating X + 3X - 4.2 when X=5, will be:

A. Multiply 3 by 5.

when X=5; X + 3X - 4.2 = 5 + 15 - 4.2

X + 3X - 4.2 = 15.8

Step-by-step explanation:

Because multiplication has priority in addition and subtraction.

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+

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