To convert Fahrenheit to Celsius, remember this equation.
Subtract 32, multiply 5, divide 9.
Or vice versa,
Multiply 9, divide 5, add 32.
So, 75°F to celsius.
75 - 32 x 5 / 9 =
Ignore PEMDAS for this.
75 - 32 = 43
43 x 5 = 215
215 / 9 ≈ 23.8
To convert to Kelvin, basically do all the steps all over again, but with one more Subtract 32, multiply 5, divide 9, add 273.15.
So, 75 - 32 x 5 / 9 + 213.15
We already know we get 23.8 from the first three steps, so just add 273.15
23.80 + 273.15 ≈ 296.95
Hope this helped :)