10d+5n=220
divide both sides by 5
2d+n=44
d=13+n
sub 13+n for d in other equatin
2(13+n)+n=44
26+2n+n=44
26+3n=44
minus 26 both sides
3n=18
divide both sides by 3
n=6
sub back
d=13+n
d=13+6
d=19
19 dimes
6 nickles
There are no numbers for this, thus you will have to use the quadratic formula.
Answer:
12.5
Step-by-step explanation:
A 10x10 grid would have 100 units. If you divide it into 8 equal units you would do:
100 / 8
Which gets you, 12.5
(45 gal/day) x (31 day/Dec) =
(45 x 31) (gal/Dec) = <em>1395 gallons</em> per December .
Choice-B is closer to that figure than Choice-A is,
but they're both poor estimates.