Answer: The answers are 13. (A) and 14. (B).
Step-by-step explanation: The calculations are as follows:
(13) The given equations are

In the attached figure (a), these two lines are drawn. We can see that The lines intersect at the point P(8, -9). So, the solution to the pair of equations is (8, -9).
Thus, the correct option is (A).
(14) The given equations are

In the attached figure (b), these two lines are drawn. We can see that The lines intersect at the point Q(7, -2). So, the solution to the pair of equations is (7, -2).
Thus, the correct option is (B).
Answer: 0.18 seconds
step by step explanation: if it takes 0.09 seconds to knock down 4 dominoes, and you are trying to find out how long it will take to knock down 8 dominoes, you can see that 8/4=2, so you need to multiply 0.09 times 2 to get your answer, which is 0.18 seconds.
There are 13 girls and 4 more students that are boys that made an A grade. Thus there are 13+4=17 students that are either girls or A students.
The probability of choosing a girl or A student is 17/30.