Assuming 0.4 is in fact, 2 divided by 5 (and not an approximation of some number that would require an infinite amount of decimal places to exactly express), then multiplication by 0.4 is the same as multiplying by 2 and dividing by 5.
This means that multiplying any rational number by 2/5 will yield another rational number (as given x/y as an input, where x and y are integers, and multiplying it by 2/5 giving 2x/5y, will mean that 2x and 5y are also integers, and the result is also rational)
If we multiply an irrational number by 2/5, however, the result will be irrational.
So your answer is any number not in the set of rational numbers, multiplied by 0.4, will yield an irrational number.
y=2X-5 and 4X-Y=7
Putting the value of Y in 2nd equation:
4x-2x+5=7
2x=7-5
2x=2
OR,x=2/2=1
putting the value of x in equation 1:
y=2x-5
y=2*1-5
y=2-5
y=-3
Answer:
B
Step-by-step explanation:
243 + 62-28 = n
243 + 34 = n
277 = n
n= 277
Answer:
%82.5
Step-by-step explanation:
- The final exam of a particular class makes up 40% of the final grade
- Moe is failing the class with an average (arithmetic mean) of 45% just before taking the final exam.
From point 1 we know that Moe´s grade just before taking the final exam represents 60% of the final grade. Then, using the information in the point 2 we can compute Moe´s final grade as follows:
,
where FG is Moe´s Final Grade and FE is Moe´s final exam grade. Then,
.
So, in order to receive the passing grade average of 60% for the class Moe needs to obtain in his exam:
That is, he need al least %82.5 to obtain a passing grade.
