Answer:
<h2>The correct answer for this question is 78.</h2>
Step-by-step explanation:
- The average or mean of any variable or mathematical phenomenon is calculated as the division of the sum of all the numbers or items within the particular variable by the total number of items or numbers within the variable.
- In this case, the marks of the 4 exams in the semester are 77,90,85 and 100 respectively.There are total 5 exams in the semester.
- Let's suppose that the marks for the 5th exam is x.
- Therefore, based on the mathematical formula to compute average or mean,to get an overall average of 86 including all the 5 exams, one has to get:-
- Hence, based on the above calculations,one has has to get 78 on the 5th exam to obtain an overall average of exactly 86.
Answer:
x = - 4 y = - 4
Step-by-step explanation:
x+y= - 8
-9x-6y=60
First, solve for x in the first equation:
x+y = - 8 Subtract y from both sides
x + y - y = -8 - y y cancels on the left
x = - 8 - y
Now plug in what you found for x into the 2nd equation and solve for y.
- 9x - 6y = 60
-9(- 8 - y) - 6y = 60 Multiply out
72 + 9y - 6y = 60
72 + 3y = 60 Subtract 72 from both sides
72 - 72 + 3y = 60 - 72 72 cancels on the left
3y = - 12 Divie both sides by 3
3y/3 = -12/3 3 cancels on the left because 3/3 = 1
y = -4
Now plug your answer for y back into the first equation to get x.
x + y = -8
x + (-4) = - 8 Add 4 to each side
x - 4 + 4 = - 8 + 4 4 cancels on the left
x = -4
x = - 4 and y = - 4
Answer:
y = -5x+11
Step-by-step explanation:
Step-by-step explanation:
Note that
Therefore,
A, X=6(x-2) as his age take away 2 (his age two years ago) then multiplied by 6 will equal his current age.
