Plant fertilizers are categorized by the percentage of nitrogen (N), phosphorous (P), and potassium (K) they contain, by weight. For example, a fertilizer that has N-P-K numbers of 8-5-5 has 8% nitrogen, 5% phosphorous, and 5% potassium by weight. Suppose that a fertilizer has four times as much potassium by
weight as phosphorous. The percentage of nitrogen equals the sum of percentages of phosphorous and potassium. If nitrogen, phosphorous, and potassium
make up 30% of the fertilizer, determine the proper N-P-K label on the fertilizer

if you mean

then it's c. 8, -7/3

but if you mean

then it is

the 8 in 8,420 is in the thousands place so it's value is 8 thousand.

the 8 in 6,870 is in the hundreds place so it's value is 8 hundred.

divide 8000 by 800 to find the answer:

8000 / 800 = 10

the 8 in 8,420 is 10 times greater than the 8 in 6,870

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.