Question

A teacher collects a total of 17 mobile phones and ipads before a group of students heads off on a bushwalk. from a second group of students, 40 phones and ipads are collected. the second group had twice the number of phones and 3 times the number of ipads than the first group. how many phones and ipads did the first group have?

Answer 1

Answer:

11 phones, 6 ipads

Step-by-step explanation:

This is a system of equations.

Group 1 had a total of 17 devices, so phones (p) + iPads (i) = 17

Group 2 had 40 devices.  They had twice the number of phones (2p) & 3 times the number of iPads (3i).

Here are the 2 equations:

p + i = 17

2p + 3i = 40

We need to eliminate a variable. I'm going to multiple=y the entire first equation by -2 to make this possible,=.

-2( p + i = 17)

This equation is now -2p - 2i = -34

Line that up with the first equation.

-2p - 2i = -34                             Add these together

2p + 3i = 40                               and you get

---------------------

i = 6

This means the first group had 6 iPads. If they had 6 iPads, then they had 11 phones to make the total of 17 devices.

Answer 2

Answer:

The phones of the first group have is 11

The ipads the first group has is 6

Step-by-step explanation:

Assuming the number of phones the first group has is x while the number of the ipads the first group has is y.

x+y=17;2x+3y=40.

x+y=17

x+y+−y=17+−y(Add -y to both sides)

x=−y+17

2x+3y=40

2(−y+17)+3y=40

y+34=40(Simplify both sides of the equation)

y+34+−34=40+−34(Add -34 to both sides)

y=6

x=−y+17

x=−6+17

x=11(Simplify both sides of the equation)

x=11 and y=6

So the number of phones the first group have is 11 and the number of ipads the first group have is 6