The concert lasts 60 minutes, and the songs are all the same length. the choir sings a total of 12 songs, 2 of which are sung by the sopranos only. for how many minutes do the sopranos sing by themselves? solve the equations using a letter for the unknown quantity.

10 minutes

Step-by-step explanation:

60 / 12 = 5

5 *2 = x=10

this means that x = 10

x =-.20752

step-by-step explanation:

4^(x+2)=12

4^(x+2)=12

take the log base 4 on each side

log 4 (4^(x+2) = log 4(12)

we know log b(a^y) = y log b (a)

(x+2) log 4(4) = log 4 (12)

x+2 = log 4 (12)

we know   logb c = loga c/loga b

we want to convert to base 10   so a = 10

by default, we do not write the 10   c = 4   and b = 10

log4 10 = log 12/log 4

log4 10 = log 12/ log 4

x+2 = log 12/ log 4

subtract 2 from each side

x +2 -2 = log 12/ log 4 -2

x = 1.79248125 -2

x =-.20752

13.46

step-by-step explanation:

16.80 x .20 = 13.46