Type the correct answer in each box. Use numerals instead of words. Consider this quadratic equation.
x2 + 2x + 7 = 21
The number of positive solutions to this equation is
The approximate value of the greatest solution to the equation, rounded to the nearest hundredth, is

The table below shows the approximate masses of a dust particle and a grain of pollen. dust particle 0.000000778 g grain of pollen 0.00000000155 g the mass of a dust particle can be estimated and written in the form a × 10^b, where a = 8 and b = the mass of a grain of pollen can be estimated and written in the form a × 10^b, where a = 2 and b = based on the estimates, the mass of a dust particle is approximately blank times larger than the mass of a grain of pollen.