Question

Question 4

Which of the following expressions is the conjugate of a complex number with −6 as the real part and −5i as the imaginary part?

6 + 5i

6 − 5i

−6 − 5i

−6 + 5i

Question 5
Simplify 81 to the negative 3 fourths power

−27

negative 1 over 27

27

1 over 27

Question 6
Find the solution of three times the square root of the quantity of x plus 5 equals negative 9

x = 4; not extraneous

x = 4; extraneous

x = 0; extraneous

x = 0; not extraneous

Answer 1

The conjugate of a complex number can be determined by arranging first the number into standard form a + bi. The conjugate has a form in which the sign of b is opposite. Hence the answer in 1 is -6 + 5i. In 2, using a calculator, the answer is 1/27. in 3, extraneous roots are roots in which when substituted to the original function, the function becomes invalid. Answer in 3 is B. x =4, extraneous.