Find x if f(x) = 2x + 7 and f(x) = -1.

Question

dustin_whitelock · Answer

x=-4


Put f(x)= y, or, y=-1;
So, y= 2x+7
or, -1= 2x+7
or, 2x=-8
or, x=-4

daniellelovee · Answer

Replace f(x) with -1 and solve PEMDAS backwards

nikkiv73 · Answer

Thank you both!

rebeccaxhawaii · Answer

Replace -1 for x.

rebeccaxhawaii · Answer

@Dustin_Whitelock Hey bud, great job but next time lets not do the work for someone, lets let them do it on their own. We are just here to guide and help them. Its a learning process, taking them step by step is more beneficial.

nikkiv73 · Answer

It really helped me - I've done 3 more problems since then because of how he wrote it out.

rebeccaxhawaii · Answer

Well that's great but he could get in trouble for doing that.

dustin_whitelock · Answer

@rebeccaxhawaii you wrote to put x =-1, but it should've been f(x)=-1.
So your solution is wrong.

rebeccaxhawaii · Answer

Oops my apologizes i just took a quick look. But i should have read more carefully. Thanks for the correction :)

dustin_whitelock · Answer

Anytime, :)