Multiply all terms by x and cancel xx+-15=2x x^2-15=2x simplify both sides x^2-15-2x=2x-2x subtract 2x from both sides x^2-2x-15=0 (x+3)(x-5)=0 factor left side of equation x+3=0 or x-5=0 set factors equal to 0 x=-3 or x=5 hope this helps!
You can estimate 3.9 times 5.3 to 4 times 5 which is 20 so if the answer is around 20, you know that you will have exactly 2 digits before the decimal place
