The slope is rise over run, how many times you go up (or if down it'd be a negative) and over.
The y-intercept is what point on the y axis the line passes through
x is less than or equal to -4 or x is greater than or equal to 5
x <= -4 or x>= 5
There is no intersection of both inequalities when we graph it in number line So, we write the interval notation separately for each inequality
for x<=-4 , x starts at -4 and goes to -infinity because we have less than symbol. Also we have = sign so we use square brackets
Interval notation is (-∞ , -4]
for x>= 5 , x starts at 5 and goes to infinity because we have greater than symbol. Also we have = sign so we use square bracket at 5
Interval notation is [5 , ∞)
Now combine both notation by a 'U' symbol Union
(-∞ , -4] U [5 , ∞)
3x-4y=10
-20-x+2y=10 then -30+2y=x now plug this in the other equation:
3(-30+2y)-4y=10
-90+6y-4y=10
2y=100
y=50
Given
12 black socks
16 white socks
Without looking, Mario takes one sock out of the drawer and then takes out another without replacing the first sock
Which expression shows one way to find the probability that he will take out two white socks?
Procedure
for the first white socks

for the second white socks