Evaluate the variable expression xyz for the given values of x, y, and z. x = 4/5 , y = −15, z = 7/8

xyz = - 21 / 2

Step-by-step explanation:

xyz = (4/5)(-15)(7/8) = (4×-15×7)/(5×1×8)

= (4×-3×5×7)/(5×1×4×2)    because:    15 = 5×3 and 8 = 4×2

xyz = - 21 / 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)

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have