Answer:
[tex]k=-4[/tex]
Step-by-step explanation:
So we have the function:
[tex]f(y)=y^2-ky-5[/tex]
And we know that f(2)=7 and we want to find k.
So, substitute 2 for y and 7 for f(y). Thus:
[tex]7=(2)^2-k(2)-5[/tex]
Evaluate the square:
[tex]7=4-2k-5[/tex]
Subtract:
[tex]7=-2k-1[/tex]
Add 1 to both sides:
[tex]8=-2k[/tex]
Divide both sides by -2:
[tex]k=-4[/tex]
So, the value of k is -4.
And we're done!
