Substituting m for 9
h(9) = 9^2 - 3*9
h(9) = 81 -27
h(9) = 54
Third option!
So basically you want to isolate only one of the variable on one side so
y=-9+x^2
add 9 to both sides
y+9=x^2
square root both sides

x=
Its 11 cause I’m built different
First of all, let’s find CB.
sin(45°) = CB : 6sqrt(2)
CB = 6
Now we can find CD
cos(60°) = x : 6
x = 3