Question

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

Answer 1

x=-4


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

Answer 2

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

Answer 3

Thank you both!

Answer 4

Replace -1 for x.

Answer 5

@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.

Answer 6

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

Answer 7

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

Answer 8

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

Answer 9

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

Answer 10

Anytime, :)