First, subtract 17 on both sides: x²+2x-16=0 this cannot be factored, so use the quadratic formula to solve for x: b²-4ac=2²-4(10(-16)=4+64=68 √68=2√17 so x=(-2+2√17)/2 or x=(-2-2√17)/2 x=-1+√17 or x=-1-√17
13 divided by 11.3 is 1.150442477876106. So 15 by 1.150442477876106 and you get 13.03846162772485. Just round it to the nearest tenth and you get 13.0.