|
We are going to go back and
look at Question 2 and go through it more slowly
and in greater detail.
First, read the
question.
Question 2:
Jane has
twice as many books as Peter. Jane and Peter
combined have 12 books. How many books do they each
have?
Then read it
again.
Jane has
twice as many books as Peter. Jane and Peter
combined have 12 books. How many books do they each
have?
There are two people
mentioned in the question, Jane and Peter.
They both have some books,
but the question doesn't tell us us how
many.
But the question does tell us
two things.
1. - That Jane has twice as
many books as Peter.
2. - That if they both put
their books together in one pile there will be 12
books
The question wants us to
determine how many books each of them
has.
The
first
thing we do is
identify the person we
don't
know anything about.
That's Peter isn't it?
Because we know something about Jane - she has
twice as many books as Peter
After the question we then
write
this line:
Let 'x' equal
the number of books Peter
has.
The 'x'
represents a number but at this stage we don't know
what the number is.
Algebra is a
way to find out that number from the other data we
are told.
In the
question we are told
that
Jane has twice as
many books as Peter.
We've already
decided that Peter has 'x', so Jane must have 2 x
'x' books, or 2x books.
The combined pile of books
will = The books Peter has + The books Jane
has.
We can now
write this in the form of an equation and then
solve
it:-
(An
equation means just two things that are
equal)s
The equation
is as follows:
The combined pile of books
will = The books Peter has + The books Jane
has
Written
numerically this becomes:
-
The
Pile------
-
Peter
--------Jane
----
-- - --
---\----
/
/-- -
- - -
-
/
----------------
12 =
x + 2x
We can add
the 'x's together so the equation
becomes:------------
-----------------
12 = 3x
- --
(Added
the x's together)
-----...
----12
÷ 3 =
x--------(We
now divide each side by 3 to get a single
'x')
----------
--..-----4
=
x------
(x =
Peter)
Answer
1:
Click on the answer below you
believe is the correct one.
Answer to
question 1:
'A' - Peter
has 4 books. Jane has 2 books
'B' -
Peter
has 4 books. Jane has 4 books
'C' -
Peter
has 4 books. Jane has 6 books
'D' -
Peter
has 4 books. Jane has 8 books
|