Well, it depends on what the weight of the test is. Most courses tell you that a test is worth a certain percentage of your grade(i.e. Final Exam is worth 20% of your entire grade). It also depends on what your grades for other assignments were, and how many there were. Try asking your teacher.
The average of your previous grade and the grade you got on your test is 84.5%. Average is the mean, which is calculated by: (91 + 78)/2.
The picture in the attached figure
let
AB=x
we know that
perimeter of the figure=10*x
perimeter=42.5 cm
so
42.5=10*x
x=42.5/10
x=4.25 cm
area of the figure=area of rectangle +area of square
area of rectangle=4.25*(4.25*3)----> 54.1875 cm²
area of square=4.25²----> 18.0625 cm²
area of the figure=54.1875+18.0625-----> 72.25 cm²
the answer is72.25 cm²
X=2y
2x+5y=9
substitute the x=2y into the second equation
2(2y)+5y=9
multiple the 2y by 2. 4y+5y=9
combine like terms. 9y=9
divide the 9 out from both sides. y=1
plug the y back into the first equation
x=2(1)
multiply. x=2
your answer is: x=2
y=1
I agree with the author. By using the metric system we know the exact amount of a medicine we took, whether it's in mg or mL. This way every doctor can prescribe the same amount.
If we were using some other units this may not be the case. For example, british and american inch were different until 1950's.
Example: if you go to a surgery and a doctor needs to cut "1 inch from the left part" it may cause a mistake as this unit is different in different countries. But if he needs to cut "2.5 cm from the left part" he knows exactly where to cut.
Another benefit of using metric system is that it is being used in almost every country in the world.
Answer:
x = 39
Step-by-step explanation:
there is a theorem that states that the midsegment in a trapezoid is equal to the sum of the bases divided by two
so, (36 + 42)/2 = x
36 + 42 = 78
78/2 = 39
