Help I need this ASAP I need 1 through 4

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?

Agroup of randomly selected apple valley high school students were asked to pick their favorite gym class. the table below shows the results of the survey. there are 528 students at apple valley high school. gym class number of students racquet sports 1 team sports 9 track and field 17 bowling 13 based on the data, what is the most reasonable estimate for the number of students at apple valley high school whose favorite gym class is bowling? choose 1 answer a. 9 b. 13 c. 119 d. 172

Alina fully simplifies this polynomial and then writes it in standard form. xy2 – 2x2y + 3y3 – 6x2y + 4xy2 if alina wrote the last term as 3y3, which must be the first term of her polynomial in standard form? xy2 5xy2 –8x2y –2x2y