Question

If the question says insert x=-5 into the equation 4^-x how would you do that? Would you say that 2 negatives equal a positive or just input -5

Answer 1

you would replace x with -5

so 4^(-x) = 4^(-(-5))

the two negatives cancel to form a positive which is why 4^(-(-5)) = 4^5

Answer 2

yeah, it equal to positive

Answer 3

ok thank you i was just confused

Answer 4

what if its a positive number then?

Answer 5

@jim_thompson5910

Answer 6

like if x = 9 ?

Answer 7

if x = 9, then,

\[\LARGE 4^{-x} = 4^{-9} = \frac{1}{4^9}\]

Answer 8

ok

Answer 9

what if x=1

Answer 10

the negative exponent tells us to take the reciprocal of the base to make the exponent positive

\[\LARGE x^{-k} = \frac{1}{x^k}\]

Answer 11

so for 2^x+3 what would x=3 be then

Answer 12

\[\Large 2^x+3\] or \[\Large 2^{x+3}\] ??

Answer 13

the second 1

Answer 14

i think the answer would be 64

Answer 15

\[\Large 2^{x+3} = 2^{3+3} = 2^6 = 64\] I agree

Answer 16

Ok thanks so much, I'm going to need more help later thou.