Question
Simplify the expression $2\left(a^2+a b\right)+3-a b$ and find Its value, when a = 5 and b =-3.
✓
Answer
We have, $2\left(a^2+a b\right)+3-a b=2 a^2+2 a b+3-a b$
$=2 a^2+2 a b-a b+3$ [rearranging terms]
$=2 a^2+a b(2-1)+3=2 a^2+a b+3$
On putting a = 5 and b = -3 we get
The value of $2 a^2+a b+3=2(5)^2+5 \times(-3)+3$
= 2 × 5 × 5 + 5(-3) + 3
= 50 - 15 + 3 = 38
Hence, the simplified expression is $2 a^2+a b+3$ and its required value is 38.
$=2 a^2+2 a b-a b+3$ [rearranging terms]
$=2 a^2+a b(2-1)+3=2 a^2+a b+3$
On putting a = 5 and b = -3 we get
The value of $2 a^2+a b+3=2(5)^2+5 \times(-3)+3$
= 2 × 5 × 5 + 5(-3) + 3
= 50 - 15 + 3 = 38
Hence, the simplified expression is $2 a^2+a b+3$ and its required value is 38.
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