PLEASE HELP FOUR PROBLEMS SUBSTITUTION AND ELIMINATION ALGEBRA!!

1.
y=-7x+10
3x+2y=9

2.
12x-10y=2
-6x+7y=-1

3.
y=5x
8x-3y=35

4.
y=-2x+28
y=5x

Do u just plot the numbers on the graph like (1,

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.

The price of a visit to the dentist is calculated according to the formula 50+100n50+100n where nn is the number of cavities the dentist finds. on your last visit to the dentist, 22 cavities were found. what was the cost of your visit?