Answer :
1x=-1
that means whererever you see x, you replace it with -1
x is a placeholder for an unknown number
so repolace it
-1+5=4
5-1=4
true
that means whererever you see x, you replace it with -1
x is a placeholder for an unknown number
so repolace it
-1+5=4
5-1=4
true
