What is the magnitude(size)of -8.5 plz help me

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Ahypothesis is: a the average squared deviations about the mean of a distribution of values b) an empirically testable statement that is an unproven supposition developed in order to explain phenomena a statement that asserts the status quo; that is, any change from what has been c) thought to be true is due to random sampling order da statement that is the opposite of the null hypothesis e) the error made by rejecting the null hypothesis when it is true

What is the point slope form of a line with slope -5 that contains point (2,-1)