4 less than five times a number is -11:
5x - 4 = -11
the answer is 2/3 and the y intercept is 2. we can find the y intercept because its where the line crosses the y axis and the slope by calculating rise and run using 2 points bebe :)
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
13. 44 + 40 = 84
14. 15 + 81 = 96
15. 13 + 52 = 65
16. 64 + 28 = 92