How much pure acid is needed to mix with 18l of 30% acid to increase the concentration of 50% acid

You and a friend race across a field to a fence and back. your friend has a 50-meter head start. the equations shown represent you and your friend's distances dd (in meters) from the fence tt seconds after the race begins. find the time at which you catch up to your friend. you: d=∣−5t+100∣d=∣−5t+100∣ your friend: d=∣−313t+50∣∣

10 points? ? +++ me asap gabriella uses the current exchange rate to write the function, h(x), where x is the number of u.s. dollars and h(x) is the number of euros, the european union currency. she checks the rate and finds that h(100) = 7.5. which statement best describes what h(100) = 75 signifies? a) gabriella averages 7.5 u.s. dollars for every 100 euros. b) gabriella averages 100 u.s. dollars for every 25 euros. c) gabriella can exchange 75 u.s. dollars for 100 euros. d) gabriella can exchange 100 u.s. dollars for 75 euros.

What is the equation of a line that passes through points (0, 4) and (-4,-8)?