21x+7y=42 and -5x+5y=10
find the solution to the system of equations

If f(x)=-x^2+6x-1 and g(x)=3x^2-4x-1,find(f+g)(x)

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.

The high temp today was 62°. when nighttime comes, the temp will drop 40°. by 4am the temp will drop an additional 40°. what is the temp at 4am?