How to do this question plz

An adult ticket costs £7.

A child ticket costs £2.

Step-by-step explanation:

Let a represent the cost for adults and let c represent the cost for children.

Family 1 has a total of 2 adults and 3 children. Together, it cost them £20.

In an equation, this is:

Family 2 has a total of 1 adult and 4 children. It cost them £15. In an equation, this is:

We know have a system of equations. Solve it. We can use the substitution method.

First, subtract both sides by 4c in the second equation:

Substitute this into the first equation:

Distribute:

Add:

Subtract 30 from both sides. The left cancels:

Divide both sides by -5:

Thus, the cost of a child ticket is £2.

Substitute 2 for c into the equation we manipulated at the start:

Thus, the cost of an adult ticket is £7.

Adult ticket= $7

Child Ticker=$2

Step-by-step explanation:

Family 1: 2x+3y=20

Family 2: x+4y=15

2x+3y=20

x+4y=15

Multiply by 2

2x+3y=20

-(2x+8y=30)

Change the signs

2x+3y=20

-2x-8y=-30

Eliminate x

-5y=-10

Divide both sides by -5

y=2< Price per children

Substitute the value of y

x+4(2)=15

x+8=15

x=15-8

x=7 <Price per adult

Check:

Substitute the values of x and y to family 1

2(7)+3(2)=20

14+6=20

20=20

7+4(2)=15

7+8=15

15=15

answer: 1722

step-by-step explanation:

given: the mass of saturn=

the mass of mercury=

the number of times the mass of saturn is greater than the mass of mercury

hence, the mass of saturn is 1722 times greater than the mass of mercury.