Phoebe, andy and polly share £270phoebe gets three times as much as andy who gets twice as much as polly. work out how much they each get.

Step-by-step explanation:

Givens

Let Phoebe = P

Let Andy = A

Let Polly = Po

Total = 270

Equations

P = 3*A

A = 2*Po

P + A + Po = 270

Solution

P + 2Po + Po = 270

P = 3*A                                       But A = 2Po. Substitue 2Po for A

P = 3(2*Po)                                 Combine the right

P = 6Po                                      Substitute 6Po for P  

6Po + 2Po + Po = 270               Combine the left

9*Po = 270                                 Divide by 9

9Po/9 = 270/9                           Do the division

Po = 30

A = 2*Po = 2* 30 = 60

A = 60

P = 3*A

P = 3*60

P = 180

Answer

Phoebe gets 180

Andy gets       60

Polly gets        30

b.) 160 miles on a 5 gallons car

step-by-step explanation:

240/10=24 miles/gallon

160/5=32 miles/gallon

30/1=30 miles/gallon

168/6= 28 miles/gallon

32 miles/gallon is the most amount, so this is the best.

hello from mrbilldoesmath!

answer:

the domain is the set { -2, 0, 2, 3}

discussion:

the domain is the set of x values in the ordered pairs (x,y). taking the x, or first component, of each ordered pair gives   -2, 0, 2, 3.

you,

mrb