Herbert gave 4 friends an equal number of baseball cards. Each friend received 18 baseball cards. Write and solve an equation to find the total number of baseball cards Herbert had. Use the letter c to represent the variable in the equation. I WILL GIVE THE BRAINLIEST!

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827