What ? thats very confusing what is the question you have to give more info
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
An x or a cross_____________
Answer : Option A
Explanation:
we can clearly see that from x+ y=5 we can substitute y = 5-x in y = 9x^2
Option B is clearly incorrect x can not be y -5
Option C is incorrect because y can not be 5 +x
Option D is incorrect because its y = 9x^2 not y^2 =9x^2 so y can not be 3x
if its y^2 = 9x^2 then only implies y = 3x