Answer:
not really sure for number one
1. 1.56y × 3.9x
2. 4.8x + 9.6y
Answer:
first thing to do is combine like terms
now you would have -x-4=4
this is because you added -6x+5x
now you would add 4 to each side
now you would have-x=8
then you would divide the negative because x has to be positive
now you would have x= -8
that is your answer. if you any questions just ask :D
Step-by-step explanation:
Let numbers of books be 'b' and numbers of CDs be 'c'
We can set up two equations:
Equation [1] ⇒

Equation [2] ⇒

We are solving for the number of books and the number of CDs bought
When we have two equations in terms of two different variables;

and

, that we need to solve, then this becomes a simultaneous equation problem.
First, rearrange Equation [1] to make either

or

the subject:


Then we substitute

into Equation [2]






Now we know the value of

which is

, substitute this value into

we have

Answer:
Numbers of books = 13
Numbers of CDs = 7