Can someone show me how to do this? What volumes of 60% hydrochloric acid solution and 30% hydrochloric acid solution must be mixed to make 125mL of 36% hydrochloric acid solution?

u need two equations. x + y = 125

0.60x + 0.30y = (0.36) (125)

x + y = 125

0.60x + 0.30y = 45

solve for a variable in the first equation

y = 125 - x

plug into the second equation

0.60x + 0.30 (125 - x) = 45

0.60x + 37.5 - 0.30x = 45

0.30x + 37.5 = 45

0.30x = 7.5

x = 25

plug the answer for x into the first equation

25 + y = 125

y = 100