how do you find the x-intercept of y = 4x - 64

*ill take an explanation before an answer, thanks

Question

how do you find the x-intercept of y = 4x - 64

*ill take an explanation before an answer, thanks

pfenn1 · Answer

An x-intercept is a point on the graph where y is zero.  so plug y into the equation and solve for x.

pfenn1 · Answer

Sorry.  An x-intercept is a point on the graph where y is zero. So plug 0 for y into the equation and solve for x.

anonymous · Answer

when i plugged in 0 for y i got 16 which wasnt my answer choice

pfenn1 · Answer

Weird.  That is what I got also.  Please double check that you copied the equation correctly and that you are looking of the x-intercept and not the y-intercept.

anonymous · Answer

attachment

pfenn1 · Answer

The equation is
$$y=4^x-64$$

anonymous · Answer

oh i see, the x is raised

anonymous · Answer

do you know this kind of problem?

pfenn1 · Answer

I think you need to use log.
$$0=4^x-64\rightarrow4^x = 64$$

anonymous · Answer

so that'l be A. (3,0)

pfenn1 · Answer

I don't remember how to solve this but I did notice that 4^2=16 and 4^3=64 so that x=3.

pfenn1 · Answer

Yes, you got it.

anonymous · Answer

Thanks for your help

pfenn1 · Answer

You're welcome.