Solve the following system of equations for X.. 3x – 2y = 8
2x + 2y = 7
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A)3
B)-3
C)15
D)1

x  =  3

Step-by-step explanation:

Solve for the first variable in one of the equations, then substitute the result into the other equation.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)