Given figure abcd ~ figure wxyz, what is the value of k?

What number should be added to both sides of the equation to complete this square? x^2-10x=7

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.

Steve had 48 chocolates but he decided to give 8 chocolats to each of his f coworkers. how many chocolates does steve have left