I have ten mins please help mee Which equation combines with the given equation to form a system of equations with the solution x = 3 and y = 9? x + 2y = 21

A.
4x + 6y = 64
B.
2x + y = 36
C.
4x + y = 21
D.
-3x + 4y = 33
E.
3x + 2y = 28

300pi

step-by-step explanation:

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

3

step-by-step explanation:

c. 1,233 miles