You can say
x+y=5
x=5-y
You know the value of x, put it into the next equation.
3(5-y)-7y=19
15-3y-7y=19
15-19 = 10y
-4=10y
-4/10=y
-2/5=y
Put y value back into either equation to find value of x.
x+y=5
x-2/5=5
x=5+2/5
x=27/5
Therefore, x,y = (27/5, -2/5)
Hope I helped :)
C 1 to 7 because 4 add 3 is 7 and 4 take away is 1 so 1 to 7 is the answer hopefully that makes sense to you.
5 and 6 inches, because it's between 5 and 6