Line 3
since he added which is against the order of opreation rule he was supposed to multiply first then add
again what he was supposed to do is
Line 2:21+5+6(2)
Line 3:21+5+12
We have to find the mass of the gold bar.
We have gold bar in the shape of a rectangular prism.
The length, width, and the height of the gold bar is 18.00 centimeters, 9.21 centimeters, and 4.45 centimeters respectively.
First of all we will find the volume of the gold bar which is given by the volume of rectangular prism:
Volume of the gold bar 
Plugging the values in the equation we get,
Volume of the gold bar 
Now that we have the volume we can find the mass by using the formula,

The density of the gold is 19.32 grams per cubic centimeter. Plugging in the values of density and volume we get:
grams
So, the mass of the gold bar is 14252.769 grams
This is the answer in exact form
Answer:
7.4
Step-by-step explanation:
- find the area of rectangular sign8times6.5)=52,take if 1l=14m^2 what about 52 then multiply by 2