let b=7 what is the value of the expression 4b2 +b -5

Answer 1

To find the value of the expression \( 4b^2 + b - 5 \) when \( b = 7 \), we can substitute 7 for \( b \) in the expression:

\[ 4(7)^2 + 7 - 5 \]

Now, calculate each part step-by-step:

1. Calculate \( 7^2 \): \[ 7^2 = 49 \]

2. Multiply by 4: \[ 4 \times 49 = 196 \]

3. Now add 7 to this result: \[ 196 + 7 = 203 \]

4. Finally, subtract 5: \[ 203 - 5 = 198 \]

Thus, the value of the expression \( 4b^2 + b - 5 \) when \( b = 7 \) is \( \boxed{198} \).