x2+10x-3=0(x+5)2-(5)2-3=0 (half the 'x' coefficient and put it in the bracket with x to be squared, then take away that new number squared followed by the original constant)(x+5)2-25-3=0 (square the number)(x+5)2-28=0 (simplify)(x+5)2=28 (add 28 to both sides)(x+5)=+/-sqrt(28) (square root both sides, it can be positive or negative)x=-5+/-sqrt(28) (take 5 away from both sides)Think about the factors of 28- 1, 28, 2, 14, 4, 7sqrt(4)=2, so sqrt(28) can be simplified to sqrt(47)=sqrt(4)sqrt(7)=2sqrt(7)So the final answer is x=-5+2sqrt(7) or x=-5-2*sqrt(7)