Final answer:
To evaluate the expression 4y + 9z with y = 5 and z = 4, substitute the values into the expression and simplify: 4(5) + 9(4) equals 56.
Step-by-step explanation:
The student is asking to evaluate the expression 4y + 9z when y = 5 and z = 4. To find the value of the expression, we substitute the given values of y and z into the expression:
4y + 9z = 4(5) + 9(4)
Now, we perform the multiplication:
4(5) = 20 and 9(4) = 36
Then, we add the results together:
20 + 36 = 56
Therefore, the value of the expression 4y + 9z when y equals 5 and z equals 4 is 56.