Shadow problems are usually solved with a proportion.
.. oak/(oak's shadow) = joey/(joey's shadow)
.. oak/(12 ft) = (6 ft)/(5 ft)
.. oak = (12 ft)*(6/5) = 14.4 ft . . . . . . . matches selection B
Simplest method: elimination.
Subtract the first equation from the second one.
(2a+b=-33)-(a+b=-10) gets you to a=-23.
Now plug that in for a and solve.
-23 +b=-10
b=13
0.75 x 500 is 375 of gold in 500 kg of ore
Answer:
Extremely large and small numbers that have many zeros are long to write and take up a lot of room. So, by using scientific notation a number can be written shorter. For example, numbers such as 295,000,000,000 can be shortened to 2.95x
. This is easier to write and understand. This is why the scientific notation is used over standard.
