7,25 x (y+5,6)=58 vậy y =

y=2,4

Step-by-step explanation:

7,25x( y+5,6)=58

7,25y+ 40,6=58

7,25y=58-40,6

y=17,4:7,25

y=2,4

x

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)