What restrictions must be made on x,x, y,y, and zz so that the triple (x,y,z)(x,y,z) will represent points on the line or in the plane described?

H the first one is correct and the second one would be 10 to the power of 4 for the 3rd one it is, Dany buys 7 boxes of crayons and each crayon box costs $3. How much will he pay? The other sentence is each pizza box costs $3 and jack orders 7 pizza boxes how much will he pay for each pizza box? For the fourth answer is, solution A I think hope this helps :)