So basically you do this ....
Hope it helps
The number 0.7 is a rational number. Hoped this helped
40 dimes is $4.00. you would need $1 in nickles. 2 nickles is 10 cents. so you would need 20 nickles.
10x+160=300
-160 -160
10x=140
divide both sides by 10
x=14
$14