What is the first part of the second step to prove that Sn => 1+ 2 + 4 + ... + 2^n - 1 =2^n -1 ?

step-by-step explanation: i dont

∠cbe and ∠deb are same-side interior angles.

i took the test

answer: bea's uncle is 25 years old.

step-by-step explanation:

given the equation , we can say that the variable "x" represents the age of bea's uncle. then to find his age, we need to solve for "x":

we must add 15 to both sides of the equation:

now we need to divide both sides of the equation by 3:

therefore, we can conclude that bea's uncle is 25 years old.