The expression we have is:
[tex]9d-4f[/tex]
And we are given values for d and f:
[tex]\begin{gathered} d=9 \\ f=8 \end{gathered}[/tex]
The first step will be to substitute these values into the expression
Step 1. Substituting d=9 and f=8 into the given expression:
[tex]9d-4f=9(9)-4(8)[/tex]
Step 2. Simplify the multiplications.
9(9) is equal to 81 and 4(8) is equal to 32, thus:
[tex]9d-4f=81-32[/tex]
Step 3. The last step is to subtract 81-32:
[tex]9d-4f=49[/tex]
This result is shown in option b.
Answer:
b) 49
