X² + 10x +2 = 0 .Complete the square of (x² + 10x + ??)
We know that (10x) is equal to twice the square root of the 1st (x) by ??
10x = 2.x.(??) and ?? = 5 and its square is 25. Then I have to add 25 and subtract 25 so that not to change the equation:
(x² + 10x + 25) -25 +2 =0
(x+5)² -23
A^2+b^2=c^2 so 4(4) +3(3) is 16+9= 25 and the square root of that is 5.
-30-27= -57
When both numbers are negative, they are “added” in a sense, but remain negative.
-5-(-4)= -1
You have to multiply the (-4) by the “invisible” -1 on the outside before you add/subtract.