Answer:
Step-by-step explanation:
$6/(2 DVDs) = $3/DVD, and $8/(4 CDs) = $2/CD
a DVD costs $3
a CD costs $2
Lynn bought 4 DVDs and 2 CDs for 4×$3 + 2×$2 = $16.
Pierre bought d DVDs and c CDs for $20.
d is 0, 2, 4, or 6
c = (20-3d)/2
(d,c) = (0,10), (2,7), (4,4), or (6,1)
.011 = 1.1* 10^-2 in scientific notation
1.1*10^-2 * 7.5 * 10^18 = (1.1*7.5) * 10 ^ (-2+18)
8.25*10^16
The sand weighs 8.25 * 16^16 grams.
I am not quite sure what the question asks for,
But this is what i assume it wants:
Cos A= 0.6489
In this given one, we basically find the size of the angle A
we do cosine inverse on both sides to get the size of the angle A
: It looks like this in the calculator
× cos A=
(0.6489)
(
and cos cancels out)
A=
(0.6489)
A=49.54°
check:
cos 49.54=0.6489 (its right!)