Did i do it right? making 227,900,000 a scientific notation ? ?

Write a function for a rotation 90 degrees counter clockwise about the origin, point 0

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

Kilgore trout creates a new scale to diagnose depression. however, his scale only assesses one symptom of depression while ignoring others. which of the following is his new scale most likely lacking? a) test-retest reliability b) discriminant validity c) criterion validity d) alternate-forms reliability e) content validity f) none of the above