Javier opens a checking account by depositing $400. He then writes checks for $29, $31 and $50. What is his balance after depositing another $50?

Anyone know? is appreciated! will mark brainliest if correct!

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x

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.