A video store is offering 20% off all outdated videos. Let s be the original price of the purchase. Use the expression s-0.2s for the new price of the purchase. Write an equivalent expression by combining like terms.

The equivalent expression is:

new price = s*0.8

Step-by-step explanation:

When the original price of something is A, and we have X% off, the new price if that object will be:

New price = A - (X%/100%)*A

Like in this case, the original price is s, and the discount is 20%

Then the new price can be written as:

new price = s - (20%/100%)*s = s - 0.2*s = s*(1 - 0.2) = s*0.8

This is the equivalent expression we wanted to get.

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)

step-by-step explanation: