Which expression are equivalent to 10x-20

Iq scores for adults age 20 to 34 years are normally distributed according to n(120, 20). in what range does the middle 68% of people in this group score on the test?

There is a spinner with 14 equal areas, numbered 1 through 14. if the spinner is spun one time, what is the probability that the result is a multiple of 2 or a multiple of 5?

Measure of angles 31 (x+4) (3x+9) me