0.542=0.500 + 0.040+0.002
= 
=5 tenth + 4 hundredths + two thousandths
One tenth = 
One Hundredth= 
One thousandth= 
If the total bill is $85, and you want to leave a 15% tip, then you can calculate it as follows:
85 * 15%
= 85 * 15/100
= 85 * 0.15
= 12.75
The amount that should be left as a tip is D. $12.75.
1/2 is the greater fraction
X²+3x-21=0
1) we solve this square equation:
x=[-3⁺₋√(9+84)] / 2=(-3⁺₋√93)/2
We have two solutions:
x₁=(-3-√93)/2
x₂=(-3+√93)/2
2) we compute the product of the 2 solutions found.
[(-3-√93)/2][(-3+√93)/2] =(-3-√93)(-3+√93) / 4=
=(9-93)/4=-84/4=-21
Answer: the product of the 2 solutions of this equation is -21