Hey!
You can make a proportion:

Cross multiply

Divide by 2

<em>5 pounds would cost $10.50</em>
Good luck and hope this helps! :)
Indeed you need to speech English
Since x=8y, subsitute 8y for x in other equation
y=6x-11
y=6(8y)-11
y=48y-11
minus y both sides
0=47y-11
add 11 to both sides
11=47y
divide both sides by 47

subsitute taht for y to find x
x=8y




in (x,y) form
(x,y)