Question

Solve -8x < 64.
A. x < 8
B. x < -8
C. x > 8
D. x > -8

Answer 1

it's B.

-8x < 64

x < 64/-8

x < -8

Answer 2

Actually it will be D, any time you divide or multiply an inequality by a negative you must change the sign. An easy way to test this is to look back at the original condition, if x were less than -8 would the product be less than 64? -8*-9=72, which is not less than 64.