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:
C
Step-by-step explanation:
If I had to make a choice it would be C. Its strange because all numbers can be divided by 4 so they all can make a square. But the closest was C.
Take -5x + y =13 and rearrange for y:
y=13+5x
Substitute into other equation for y:
-3x+3(13+5x)=3
Multiply out brackets:
-3x+39+15x=3
Simplify:
12x+39=3
Rearrange for x:
12x=-36
x=-3
Substitute back into y=13+5x:
y=13+5(-3)
y=13-15
y=-2
Answer:You do not have a question i can not answer it
Step-by-step explanation:
Sorry
Answer:
Okay....I can help.............
