Answer:
There are 150 blue marbles in Alex's bag.
Step-by-step explanation:
Let
,
,
be the quantities of red, blue and yellow marbles, respectively. From statement we derive three rational equations for initial and final ratios:
Initial ratio
(1)
(2)
Final ratio
(3)
After some algebraic handling we get the following system of linear equations:
(1)
(2)


(3)
The solution of the system of linear equations is:
,
, 
There are 150 blue marbles in Alex's bag.
Answer:
Hey there!
Expand (2+i)(3-i). You should get 7+i
Expand (7+i)(1+2i). You should get 5+15i
Expand (5+15i)(1-i). You should get 20+10i
Expand (20+10i)(3+i). You should get 50+50i as your final answer.
Let me know if this helps :)