Find two consecutive positive integers such that thw sqaure of the first decreased by 25 equa; s three times the second

Consecutive integers are 1 apart

so

square of the first decreased by 25 equals 3 time the 2nd
the 2 integers are x and x+1

x²-25=3(x+1)
distribute
x²-25=3x+3
minus (3x+3) from both sides
x²-3x-28=0
factor
what 2 numbers muliply to get -28 and add to get -3
-7 and 4
(x-7)(x+4)=0

set to zero

x-7=0
x=7

x+4=0
x=-4
false, we want positive integers

x=7
x+1=8

the inegers are 7 and 8

The answer of the above question is

Ac equals 35 cm long