John has $20.43 dollars in his pocket. he buys a tv for $15.39 dollars. how many dollars does john have left?

Evaluate the expression for the given value of the variable 2×(c2-5) for c=4

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

Timmy uses 1 1 2 cups of sugar for every 2 gallons of lemonade he makes. how many cups of sugar would timmy use if he makes 13 gallons of lemonade?