What are some applications of the field of spectroscopy? check all that apply. for identifying elements in a sample for determining the distance and velocity of galaxies for producing neon lights for determining types of chemical bonds for use in medical imaging devices for killing bacteria in foods

A. for identifying elements in a sample

B. for determining the distance and velocity of galaxies

C. for producing neon lights

D. for determining types of chemical bonds

E. for use in medical imaging devices

Explanation:

linda: 3 ; laura: 15

step-by-step explanation:

note that linda + laura's age is 18, and that linda is 12 years younger than her sister.

let "linda" = x , "laura" = y:

x + y = 18

x = y - 12

first, plug in y - 12 for x in the first equation:

(y - 12) + y = 18

simplify.

2y - 12 = 18

isolate the variable (y). note the equal sign, what you do to one side, you do to the other. do the opposite of pemdas. first add, then divide.

2y - 12 (+12) = 18 (+12)

2y = 18 + 12

2y = 30

(2y)/2 = (30)/2

y = 30/2

y = 15

next, plug in 15 for y in the second equation (the other equation would work too).

x = y - 12

x = (15) - 12

x = 3

linda's age is 3, laura's age is 15.

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i need mutiple choices