Multiply both sides of the second equation by 100 to get rid of the decimals:
0.05<em>n</em> + 0.10<em>d</em> = 1.50
==> 5<em>n</em> + 10<em>d</em> = 150
Multiply both sides of the first equation by -5:
<em>n</em> + <em>d</em> = 21
==> -5<em>n</em> - 5<em>d</em> = -105
Add the two equations together:
(5<em>n</em> + 10<em>d</em>) + (-5<em>n</em> - 5<em>d</em>) = 150 + (-105)
Notice that the terms containing <em>n</em> get eliminated and we can solve for <em>d</em> :
(5<em>n</em> - 5<em>n</em>) + (10<em>d</em> - 5<em>d</em>) = 150 - 105
5<em>d</em> = 45
<em>d</em> = 45/5 = 9
Plug this into either original equation to solve for <em>n</em>. Doing this with the first equation is easiest:
<em>n</em> + 9 = 21
<em>n</em> = 21 - 9 = 12
So Donna used 12 nickels and 9 dimes.
Answer:
What expressions are equivalent to 20
Step-by-step explanation:
since you didn't .show a link this is my guess, i guess.
4x5=20
Answer: false
explanation;
Answer:
The number of boys in the school is;

Explanation:
Given that the ratio of boys to girls in a school is 5:4;

And there are 500 girls in the school.
The number of boys in the school will be;

Therefore, the number of boys in the school is;
Ok so the first thing to do would be get rid of the fraction. To do that multiply the ENTIRE equation but the denominator. Once all the numbers are multiplyed I think it’ll be easier for u to solve them :) or if u wanna solve them quick, download Photomath :)