2x+9−5x=12 i dont under stand how to get the answer

(a) (8%) compute the probability of an even integer among the 100 integers 1! , 2! , 3! , until 100! (here n! is n factorial or n*(n-1)*(n-2) *… 1) (b) (16%) compute the probability of an even integer among the 100 integers: 1, 1+2, 1+2+3, 1+2+3+4, …., 1+2+3+… + 99, and 1+2+3+… + 100

Write the slope-intercept form of the line that passes through the point (1, 0) and is parallel to x - y = 7. t

What are two numbers that have a sum of 15