Don’t invest too much into it
108 mins✍ 48÷4=12 1 sprinkler takes 12 mins 48+48=96 = 8 sprinklers 1 more equals 12 so 96+12=108
If x>4, then the quantity x-3 inside the absolute value symbol is already positive. So, in this case, |x-3| => x-3, and x-3 is all you need to write.
Find out yourself.best of luck
last one. i can do the first part. put x = distance from top of ladder to the floor, y = distance from base of ladder to the wall (draw a picture) then pythagoras sez
<span><span>x2</span>+<span>y2</span>=25</span>
calculus says
<span>2x<span>x′</span>+2y<span>y′</span>=0</span>
and you are told that
<span><span>y′</span>=2</span>
so you know
<span>2x<span>x′</span>+4y=0</span>
or
<span><span>x′</span>=−<span><span>2y</span>x</span></span>
