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.
She is correct because a negative subtracted by a negative is positive.
Answer:
C) 240
Step-by-step explanation:
b = 20 cm
h = 12 cm
<h3>Area = b . h</h3>
= 20 . 12
= 240 cm²
<h3>#CMIIW</h3>
Answer:
<h2>The required answer is 218 degree.</h2>
Step-by-step explanation:
∠AOB = 90 degree.
∠BOC = 52 degree.
Arc CDE = 180 degree, since CE is the diameter.
Hence, Arc EAC = 180 degree.
Besides, Arc EAC = Arc EA + Arc AB + Arc BC = Arc EA + 90 + 52 = Arc EA + 142.
Thus, Arc EA = 180 - 142 = 38 degree.
Arc ADC = 180 + 38 = 218 degree.