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:
21
Step-by-step explanation:
15 + 6= 21
so 21-6= 15
there for your answer would be 21
Mark me brainliest plz
Answer:
33
Step-by-step explanation:
3∙[ 9 – 2∙ (7 – 8)]
PEMDAS,
Parentheses, start from the inside out
3∙[ 9 – 2∙ (-1)]
3∙[ 9 +2]
3* 11
33
Answer:
14,1 cm
Step-by-step explanation:
If a circle passes through the vertices of a square then the diagonal of a square is a circle diameter.
We use Pytagoras Theorem to find out the length (L) of the diagonal given that:
L² = (20)² + (20)²
L² = 2* (20)²
L = √2 * 20
L = 1,4142* 20
L = 28,28 cm
L diagonal in the square is a diameter of the circle then radius of a circle is:
r = L/2 ⇒ r = 28,28 /2 ⇒ r = 14,14 cm
