Let N be no. of nickles. Then N($.05)+3N($.10)+2N($.25)=$3.40.
Or
4 nickels = $0.20
12 dimes = $1.20
8 Quarters = $2.00
Total = $3.40
x=11
x is equal to 11 because you subtract 4x from both sides and then add 8 to both sides where you are left with 2x=22. After dividing by 2, you get x=11
About 492 feet per minute
9 • 54.68066 = 492.126
Rounding to the nearest whole number gets you 492
41+0.10x = 31+0.15x
10 +0.10x=0.15x
10=0.05x
x=10/.05
x= 200 text messages
check 200*0.10 = 20 +41 =61
200*0.15 = 30+31 = 61
they equal each other so number of texts is 200