Sandy mixed 9 ml of an acidic solution with 8 ml of a 42% acidic solution, to make a 45% acidic solution. find the percent acid concentration of the first solution.

47.67%

Step-by-step explanation:

Amount of 1st solution = 9 ml

Let the percentage acid concentration of 1st solution is x%

Amount of 2nd solution = 8 ml

Percentage acid concentration of 2nd solution = 42%

Percentage acid concentration of the mixture = 45%

Amount of the mixture = 8 + 9 = 17 ml

1st Solution + 2nd Solution = Mixture

x% of 9 ml + 42% of 8 ml = 45% of 17 ml

Thus, the percent acid concentration of first solution is 47.67%

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.