how can you decide which variable to solve first when you are solving a linear system by substitution​

Closing a credit card usually _your debt ratio.a. increasesb. decreasesc. improvesd. has no effect on

Pls the last one and it has to be like number 6

Astudent found the solution below for the given inequality. |x-9|< -4 x-9> 4 and x-9< -4 x> 13 and x< 5 which of the following explains whether the student is correct? -the student is completely correct because the student correctly wrote and solved the compound inequality. -the student is partially correct because only one part of the compound inequality is written correctly. -the student is partially correct because the student should have written the statements using “or” instead of “and.” -the student is completely incorrect because there is no solution to this inequality.