It’s A. The first option. Also pls brainlist
She will use 42 purple beads.
Explanation
We will use a proportion to solve this.
The ratio of blue to purple beads is 4:3, or 4/3.
We know she uses 56 blue beads and an unknown amount, x, of purple beads. This gives us 56/x.
Together, we have
4/3 = 56/x
Cross multiply:
4*x = 3*56
4x = 168
Divide both sides by 4:
4x/4 = 168/4
x = 42
Rx - sx + y = b
WHEN SOLVING FOR X :
rx - sx + y = b
We must get x onto it's own side, so subtract y from both side.s
rx - sx = b - y
Then, factor out x.
x(r - s) = b - y
Then, divide both sides by (r - s).
x(r - s) ÷ (r - s) = b - y ÷ (r - s)
Simplify.
x = b - y / r - s →

WHEN SOLVING FOR Y :
rx - sx + y = b
We need to isolate y, so get rid of everything BUT y on the left side.
Subtract rx from both sides.
-sx + y = b - rx
Then, add sx to both sides.
y = b - rx + sx
~Hope I helped!~
To find what profit they made, subtract what they earned from what they spent money on. 275-55=220. They made a total of $220 after paying for supplies. I hope this helps! :)