Answer:
35 [$]
Step-by-step explanation:
1) if Peter's sum is p and Jacky's is j, then the ratio 5:2 in the condition can be written j/p=5/2;
2) the phrase 'after Jacky gave 15 dolls to Peter, they have an equal number of dolls' can be written as j-15=p;
3) using the two above it is possible to make up the system of two equations:

4) finally, the have together 10+25=35 doll-s.
V = 1/3 * 3.14 * 11 * 6^2 = 414.48 m^3
cost = V * 20 = 414.48 * 20 = 8289.60
So legnt=l
width=w
l=-7+3w
l=3w-7
area=66
area=legnth times width or
area=lw
subisutte
area=lw
l=3w-7
66=(3w-7)(w)
66=3w^2-7w
subtrac 66 from both sides
0=3w^2-7w-66
factor
HOW TO
multiply 3 and -66=-198
find what 2 numbers add up to -7 and multiply to get -198
the numbers area 11 and -18
so
3w^2-18w+11w-66=0
factor
(3w^2-18w)+(11w-66)=0
(3w)(w-6)+(11)(w-6)=0
factor using distributive (ab+ac=a(b+c))
(3w+11)(w-6)=0
set them to zero
3w+11=0
subtract 11
3w=-11
legnths cannot be negative so we discard this
w-6=0
add 6
w=6
width=6
legnth=3w-7
length=3(6)-7
legnt=18-7
legnth=11
width=6
legnth=11
Multiply <span>3/8 inch by 75 and divide by 5</span>