Step-by-step explanation:
1. -9x - 3 - 3 + 2x
-7x - 6
3. 3 - 4x - 7x - 2
-11x - 1
4. 5x - 1 + 3 + 2x
7x + 2
65:36 cannot be simplified. It would turn into a decimal number and we don’t put decimals in ratios
Answer:
132600
Step-by-step explanation:
I was always taught like this, and this should be the best estimate:
28 x 4417 --> 30 * 4420 --> 132600
Some other possible estimates with simpler values:
30 * 4400 --> 132000
30 * 4500 --> 135000
30 * 4000 --> 120000
<u>the question is </u> Calculate the value of the copper in the coin
Step 1
Find the volume of the coin
we know that
the volume of a cylinder is equal to

where
r is the radius of the coin
h is the thickness of the coin
in this problem we have
Diameter=19 mm=1.9 cm
r=D/2------> r=1.9/2=0.95 cm
h=1.5 mm=0.15 cm
substitute the values in the formula

Step 2
<u>Find the mass of copper in the coin</u>
we know that
the density is equal to

Solve for the mass

we have

substitute in the formula

Step 3
<u>Find the cost</u>
we know that
the market price of the copper is $2.15 per pound
1 pound=453.592 grams
convert gram to pounds
3.785 gr=3.785/453.592=0.0083 pounds
0.0083*$2.15=$0.018=$0.02
therefore
<u>the answer is</u>
$0.02
0.732
0.750
If you have trouble with decimals, then multiply both numbers by a constant number to get rid of the decimals. In this case, we would multiply by 1000.
0.732 x 1000 = 732
0.750 x 1000 = 750
Obviously, 750 is bigger than 732. Therefore, 0.75 is bigger than 7.32.
By the way, this is a property:
If

, then