<p>I don't understand how to get these answers, could someone please explain how. Thanks</p>
<p>p.522 </p>
<p>17.) In the xy-plane, line l passes through the origin and is perpendicular to teh line 4x +y = k, where k is a constant. If the two lines intersect at the point (t, t+1), what is the value of t?</p>
<p>Answer: (A) -4/3</p>
<p>20.) When 15 is divided by the positive integer k, the remainder is 3. For how many different values of k is this true?</p>
<p>Answer: (C) 3</p>
<p>See the sticked consolidated thread for two threads about the first problem. </p>
<p>For the second one, you know that all k's will be divisors of 12. However, not all divisors of 12 are possible solutions since some of them have multiples between 12 and 15. Check the divisors of 12 (1,2,3,4,6,12) by dividing 15 by each divisor and seeing if the remainder is three. You will find that only 4, 6, and 12 are possible values of k</p>
<p>Thanks, that other consolidated thread is awesome.</p>