Answer:
14 quarters and 28 nickels
Step-by-step explanation:
System of Equations where x = number of quarters and y = number of nickels
(1) equation with value of each coin
0.25(x)+0.05(y) = 4.90
(2) total number of coins
x + y = 42
Solve system of equations using either substitution or elimination
(elimination multiplying equation 2 by -0.5)
.25(x) + 0.05(y) = 4.90
-0.05(x) - 0.05(y) = 42 * (-0.05)
(3) Resulting equation
.20(x) = 2.8
x = 14
plug x into equation 2
14 + y = 42
y = 28
There are 14 quarters and 28 nickels in Mary's collection.
C = # of carpenter hrs , b = # of blacksmith hrs
c + b = 30...c = 30 - b
20c + 25b = 690
20(30 - b) + 25b = 690
600 - 20b + 25b = 690
-20b + 25b = 690 - 600
5b = 90
b = 90/5
b = 18 <== hrs worked as blacksmith
c + b = 30
c + 18 = 30
c = 30 - 18
c = 12 <== hrs worked as carpenter
the answer is a n b
Step-by-step explanation:
6(2(5) - 4)
6(10 - 4)
6(6)
36
Answer: f=26
Step-by-step explanation: x^2+6x^2+12x+7/x= 26
