MCQ
Evaluate: $b^2- 9 (b - 1)^2,$ if $b = 1.1:$
- ✓$1.12$
- B$1.21$
- C$1.02$
- D$1.11$
✓
Answer
Correct option: A.
$1.12$
We substitute $b=1.1$ in the equation $b^2 - 9 (b - 1)^2$ as follows:
$b^2 - 9 (b - 1)^2$
$= (1.1)^2 - 9 (1.1 - 1)^2$
$= 1.21 - 9 (0.1)^2$
$=1.21 - (9 × 0.01)$
$=1.21 - 0.09 = 1.12$
$b^2 - 9 (b - 1)^2$
$= (1.1)^2 - 9 (1.1 - 1)^2$
$= 1.21 - 9 (0.1)^2$
$=1.21 - (9 × 0.01)$
$=1.21 - 0.09 = 1.12$
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