Absolute value

[beater]

If x and y are integers and y = |x+3|+|4-x| , does y equal 7 ?

1) x < 4
2) x > -3

Can we solve this without substituting numbers?

[Ian Stewart]

I explained a conceptual approach to the problem here:

www.beatthegmat.com/og-ds-absolute-valu ... 32674.html