Question

HELPPP

Answer 1

I'm not sure if it only wants you to find Equation 1 or go further and solve:

x = the number of 5c coins

y = the number of 10c coins

Equation 1: the total number of coins is 65

x + y = 65

total value of $3.80

0.05x + 0.1y = 3.8

Simultaneous Equations

Make one coefficient the same

10 * (0.05x + 0.1y = 3.80 = 0.5x + y = 38

x + y = 65

0.5x + y = 38

Subtract the equations

(x + y) - (0.5x + y)= 65 - 38

(x - 0.5x) + (y - y) = 65 - 38

0.5x = 27

x = 54

Substitute it into the original equation to find y.

x + y = 65

54 + y = 56

y = 65 - 54 = 11

Substitute it into the other equation to check it's right.

0.05x + 0.1y = 3.8

0.05(54) + 0.1(65) = 3.8

x = 54 5c coins

y = 11 10c coins