Y=-6.75x + 8.54 slope and y intercept

The axis of symmetry for the graph of the function f(x)=1/4^2+bx +10 is x=6. what is the value of b?

Tomas is making trail mix using granola and walnuts. he can spend a total of $12 on the ingredients. he buys 3 pounds of granola that costs $2.00 per pound. the walnuts cost $6 per pound. he uses the equation to represent the total cost, where x represents the number of pounds of granola and y represents the number of pounds of walnuts. he solves the equation for y, the number of pounds of walnuts he can buy. answer- b tomas added 6 to both sides of the equation instead of subtracting 6. just took the test

The table above shows approximate conversions from gallons to liters. what is the value of x?