Step-by-step explanation:
X + 9= 7
get x by itself you -9 on both sides
X + 9 = 7
- 9. -9
X = -2
1/x + 1/y = 8
x + y = 8
6/x + 12/y = 72n
$20 bought 16 songs
Therefore each song costs $20/16 = $5/4 = $1.25
So:
2 songs would cost 2 * $1.25
3 songs would cost 3 * $1.25
...
x songs would cost x * $1.25
Since Renata started with $20, then her balance (y) after buying x songs would be:
y = 20 - 1.25*x
A. hope this helps I’m pretty sure it’s right though
