Ok so first, write down the equation. We know that x=3 and y=4. You just basically plug in the terms into the variables. So it would be 3(3)+1/4(4)^2. Simplify that equation and you should get your answer :)
Write and solve an equation of ratios:
oil 8 x
---- = ---- = -----------
vin 5 7 liters
Then 5x = 56, and x = 56/5 liters (of vinegar)
Terry has 43 in her checking account....she then writes a check for 62...
43 - 62 = - 19 <==