Question

The cost of 3 notebooks and four pencils is $8.50. The cost of 5 notebooks and 8 pencils is $14.50. Determine the cost of one notebook and the cost of one pencil. Only in algaebraic solution.

Answer 1

let notebook = x and pencil =y
so 3x+4y=8.50
and 5x+8y=14.50
so now that you have formed your simultaneous equations, you can find x and y

Answer 2

thanks but can u explain to me how to solve equations like this thank You

Answer 3

alright, sure
so first of all, we need to either make the x's the same or the y's the same
like 3x and 5x should be a common number such as 15x

Answer 4

or to make it easier, you can just make the y's the same by multiplying the first equation by 2 in order to 8y

Answer 5

2(3x+4y=8.50) = 6x+8y=17 <---1st equation
5x+8y=14.5 <---- 2nd equation

Answer 6

now that your y's are the same, you can cancel them out by subtracting, meaning 8y-8y = 0
now since you subtracted the y's you have to subtract everything else also

Answer 7

meaning it would be 6x-5x=17-14.5
so x=2.5

Answer 8

after this, you substitute this value of x into any one of the above equations to get your value of y : (I'm using the first equation) : 6(2.5) + 8y =17
so 15+8y =17
hence 8y = 2 and your y is 2/8 which is 1/4 or 0.25 in decimals

Answer 9

Thank You soooo very much :D

Answer 10

and to make sure that your answer is correct, you can substitute your calculated x and y values back into both equations to see if you get the right answers

Answer 11

you're welcome :) i hope you understood it

Answer 12

U just gained a fan :D