Answer:
Number of nickels: 2,
Number of dimes: 6
Step-by-step explanation:
Say d ⇒ number of dimes, n ⇒ number of nickels; from this we can formulate two equation knowing the cost per dime ⇒ $ 0.1, and the cost per nickel ⇒ $0.05
d + n = 8,
0.1 * d + 0.05 * n = 0.7 ⇒ Let us solve through substitution
d = 8 - n into 0.1 * d + 0.05 * n = 0.7,
0.1 * ( 8 - n ) + 0.05 * n = 0.7,
0.8 - 0.1 * n + 0.05 * n = 0.7,
0.8 - 0.1n + 0.05n = 0.7,
- 0.05n = - 0.1,
Number of nickels: 2 ⇒ Now let us substitute this value into the first equation as to solve for d, dimes
d = 8 - 2,
Number of dimes: 6
