(7a-b)(7a+b) simplify the following. solve

49a^2-b^2

Step-by-step explanation:

(7a-b)(7a+b)        

7 x 7^                        Combine liked terms

a + a -b + b

49a^2-b^2

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)