Answer:
12
Step-by-step explanation:
Rearrange into the form y = mx + c, where m is the slope.
12x - y = 30
y = 12x - 30
m = 12
Answer:
(A) 21
Step-by-step explanation:
5x-15 needs to equal 90 since it is a right angle and 21 makes that true

In a four-digit number, the first digit cannot be 0, so there are only 4 even numbers available. For the second, third, and fourth digits, there are 5 available numbers. Thus, the number of 4-digit numbers containing only even digits is 4 x 5 x 5 x 5 = 500 numbers.