Final answer:
To evaluate 4a^2+3 when a=5, substitute the value of a into the expression and simplify.
Step-by-step explanation:
To evaluate 4a^2+3 when a=5, we substitute the value of a into the expression. Since a=5, we have:
4(5)^2+3
Simplifying, we get:
4(25)+3
Which further simplifies to:
100+3
Finally, adding 100 and 3, we get the answer:
103