Question

Help please, thank you!​

Answer 1

8 dimes and 9 nickels

Explanation:

In this exercise, we got a system of linear equations. We can solve this system by using several methods: substitution, reduction and equalization, and other advanced method call "Cramer's rule".

So, for this exercise we will use the substitution method.

1. Clear n for the first equation.

n + d = 17

n = 17 - d

2. Replace n in the second equation.

0.05n + 0.10d = 1.25

0.05(17 - d) + 0.10d = 1.25

0.85 - 0.05d + 0.10d = 1.25

0.85 + 0.05d = 1.25

3. We solve the obtained equation for d.

0.05d = 1.25 - 0.85

d = (1.25 - 0.85)/0.05

d = 0.40/0.05 = 8

dimes (d) = 8

4. we obtain the value of n using any of the two equations and with d = 8

Using the first equation

n + d = 17

n = 17 - d with d = 8

n = 17 - 8

n = 9

nickels (n) = 9

.

Answer 2

9 nickels 8 dimes

EXPLANATION

The simultaneous equations are:

1st equation: n+d=17

2nd equation: 0.05n+0.10d=1.25

Multiply through the second equation by 100.

This the equation:

3rd equation: 5n+10d=125

Make n the subject in equation (1).

n=17-d

Substitute this into equation (3)

5(17-d)+10d=125

85-5d+10d=125

-5d+10d=125-85

5d=40

Divide both sides by 5.

d=8

Put d=8 into n=17-d

This gives:

n=17-8

n=9