40! / 30! = 40*39*38*37*36*35*34*33*32*31
dividing this by 10! 10*9*8*7*6*5*4*3*2*1
= 4*13*19*37*17*11*4*31
= 847,660,528
KJ^2=6^2+3^2
KJ=the square root of 36+9
KJ=square root of 45
kJ= 3 times the square root of 5
The answer is D
Your question answers itself. You solve by graphing.
I like to subtract one side of the equation from the other, so the solutions are where the graph crosses the x-axis (the resulting function value is zero).
It can be useful to find the "turning point" of each absolute value expression (where its value is zero) and graph that and some points on either side.
So, we'll say Mia gets $4.50 a day, since a standard weekend is two days, therefore adding up to $9 a weekend. So if Mia were to do her chores for 4 weekends, she'd have a total of $36 but not $40. So if she were to work an extra weekend, so 5 weekends, she'd have a total of $45. So you can say 5 weekends in order to earn more than $40.
