Can someone plz help me solved this problem I need help plz help me! Will mark you as brainiest!

Answer:
4
4
Step-by-step explanation:
x litres of 15% solution + y litres of 19% solution= 8 gallons of 17% solution
disinfectant content of the final solution= 8*0.17= 1.36 gallons
0.15x+0.19y=1.36
x+y= 8 ⇒ x=8-y