HI,
Thanks in advance for your help.
On the Foundations of GMAT MATH BOOK - Equations
Page #279
Equation y-x=4... was multiplied by -1 so it can be expressed x follow by y ... The result was -x+y= -4 ( To me this is the correct way)
But I noticed that on pag 276, equation y-x= -7
They didn't apply the -1 to ( -7) Result on the book was -x+7=-7
The same thing happened on pag # 262 problem # 8, answer on pag 284, Equation y-x= -5 Result -x+y= -5
They didn't apply the -1 to (-5)
Why is that?