Question

If $21bx-28>49$, Where b is a positive constant, which of the following best describes all possible values of 4 - 3bx?

• A. Any value less than -7
• B. Any value greater than -7
• C. Any value less than $-\frac{11}{3b}$
• D. Any value greater than $\frac{11}{3b}$

Answer 1

The correct option is A Any value less than -7

Let examine the given inequality $21bx-28>49$
Dividing both side by 7
$\frac{21bx}{7}-\frac{28}{7}>\frac{49}{7}$
$3bx-4>7$
Multiply -1 on both side [remember to flip the sign]
$-1(3bx-4)<7(-1)$
$4-3bx<-7$
The correct answer is option A.