You can put this solution on YOUR website! (10a+5m=12.00)*15 ==> 150a+75m=180 (solving simultaneous equations)
(15a+4m=14.50)*10 ==> 150a+40m=145
35m=35, m=1,
put m=1 in equation 15a+4m=14.50 ==> 15a=14.5-(4*1)=10.5
a(apple)=10.5/15=0.7 for 1 apple 0.7$
m(mango)=1$. for 3 mangoes 3$