4w-7k=28
-7k+4w+-4w=28+-4w
-7k=-4w+28
-7k/-7=-4w+28/-7
k=4/7w-4
:)
Answer:
we have, 1953125=5⁹, so it cannot be a perfect square. If the last digit of a given number is 5, then the last three digits must be perfect squares, 025 or 225 or 625. Otherwise, that number cannot be a perfect square. And as 125 is not a perfect square, so no number ending with 125 can be a perfect square
Let, Number of multiple choice = x
Number of short answer question = y
Now, x + y = 20
& 3x + 11y = 100
Multiply 1st equation by 3, and subtract from eq,2,
3x + 3y = 60
After subtraction,
8y = 40
y = 40/8
y = 5
Now, substitute in eq (1),
x + 5 = 20
x = 15
In short, There are 15 Multiple choice & 5 short answer questions
Hope this helps!