The line y = 2x +k is a tangent to the curve x² + 2xy + 20 = 0. a Find the possible values of k.
b For each of these values of k, find the coordinates of the point of contact
of the tangent with the curve.​

1c) the number 131 is a term in the sequence defined by the explicit rule f(n)=5n-4. which term in the sequence is 131? 2a) write the first four terms of the function f(n)=n^2-1 2b) what is the 10th term of the sequence defined by the explicit rule f(n)=n^2-1 2c) the number 224 is a term in the sequence defined by the explicit rule f(n)=n^2-1. which term in the sequence is 224?

Asurvey of 2,000 doctors showed that an average of 3 out of 5 doctors use brand x aspirin.how many doctors use brand x aspirin

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"