First add the biggest number like thousand together and the go in to the last numbers
Hello,
s=48t-16t²
a)
s=0==>16t(3-t)=0==>t=0 or t=3
b)
s>32==>48t-16t²>32===>16(t²-3t+2)<0
Δ=9-8=1
==>16(t-1)(t-2)<0
==>1<t<2 (negative between the roots)
85/15 is 5 2/3
so, to find 85% with 15%, you would multiply 12 (also 15%) by 5 2/3.
12*5 2/3=68.
you could also find it using the 1% method:
1% of 15 is .15.
.15*85=68.
Hope this helps!