How many different four-letter secret codes can be formed if the first letter must be an S or a T?

What is the value of x? enter your answer in the box. photo attached.

1- identificar select the category that corresponds to each term. january 23 11: 59 pm unlimited attempts remaining grade settings 276-279 vocabulary list modelo fiesta quinceañera casada adolescencia viudo juventud navidad niñez vejez aniversario de bodas divorciado madurez cumpleaños soltera

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.