Question 1188262
x = the amount invested at 5%.
y = the amount invested at 4.5%.


you have two equations that need to be solved simultaneously.
they are:


x + y = 120000
.05x + .045y = 5800


multiply both sides of the first equation by .05 and leave the second equation as is to get:


.05x + .05y = 6000
.05x + .045y = 5800


subtract the second equation from the first to get:


.005y = 200


solve for y to get:


y = 200 / .005 = 40000


since x + y = 120000, then x = 80000.


your solution is that she needs to invest 80000 in the internet cafe and 40000 in the photo booth.


confirm by replacing x and y in the original equation with 80000 and 40000.


you get:


x + y = 80000 + 400090 = 120000
.05x + .045y = .05*80000 + .045*40000 = 5800.


your solution is confirmed to be good.