Question

Which equation has two real solutions?

A. x2 = –100
B. 5x2 = 1
C. 6x2 + 17 = 11
D. 7(x2 + 6) = 42

Answer 1

B. 5x² = 1

Explanation:

A. x² = –100

This equation has no solution because x² is always positive.

B. 5x² = 1

then x² = 1/5

then x = 1/(√5) or x = -1/(√5)

C. 6x² + 17 = 11

then 6x² = 11 - 17 = -6

then x² = -6/6 = -1

This equation has no solution because x² is always positive.

D. 7(x + 6) = 42

then x + 6 = 42/7 = 6

then x = 6 - 6 = 0

_____________________

:)