Z - 2.3 = 5.75

i need help

Ateacher has $80 to buy workbooks. each work book cost $3. if she buys as many workbooks as possible, how much money does she have leftover? a) $2 b) $4 c) $6 d) $8

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

What will the graph look like for a system of equations that has no solution? a. the lines will be perpendicular. b. the lines will cross at one point. c. both equations will form the same line. d. the lines will be parallel.