2(3x - 4) + 10 = 5(x + 4)

solving equations from book (geometry common core)

x = 18

Step-by-step explanation:

Given

2(3x - 4) + 10 = 5(x + 4) ← distribute parenthesis on both sides

6x - 8 + 10 = 5x + 20, that is

6x + 2 = 5x + 20 ( subtract 5x from both sides )

x + 2 = 20 ( subtract 2 from both sides )

x = 18

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)

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons