There is one cake
It is divided among x family members, so each gets:
1/x
The father took 1/5 which is 4 times greater than each one's piece. So:
1/5 = 4(1/x)
1/5 = 4/x
x = 20
There are 20 family members so the answer is none of these
X² + y² - 4 x + 2 y = b
x² - 4 x + 4 + y² + 2 y + 1 = b + 4 + 1
( x - 2 )² + ( y + 1 )² = b + 5
y - coordinate of the center of the circle is: y = - 1
b + 5 = r
b + 5 = 7
b = 7 - 5
b = 2
3. You should write down the problem and watch tutorials.
