Answer: when a = 3, b = 2, and c = 9, the value of the expression 5ab + 6c is 84.
Explanation:
To find the value of the expression 5ab + 6c when a = 3, b = 2, and c = 9, we can substitute the given values into the expression.
Step 1: Substitute the values of a, b, and c into the expression.
5(3)(2) + 6(9)
Step 2: Simplify the expression.
30 + 54
Step 3: Add the numbers.
30 + 54 = 84
Therefore, when a = 3, b = 2, and c = 9, the value of the expression 5ab + 6c is 84.