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:
time taken = 2.74 seconds
Explanation:
We are given that:
y = -16t² + 120 models the situation where:
y is the floor number
t is the time taken for the apple to hit the ground
We are also given that the floor number (y) is 10. Therefore, all we have to do is substitute with y in the above equation and solve for the time t as follows:
y = -16t² + 120
10 = -16t² + 120
120 - 10 = 16t²
110 = 16t²
t² = 110/16
t² = 6.875
either t = 2.74 seconds ..........> accepted
or t = -2.74 seconds .........> rejected as time cannot be in negative
Hope this helps :)
Answer:
3:6
3x2=6
Scale factor = 2
Step-by-step explanation:
Answer:245
Step-by-step explanation:
hope this helps
Answer:
She has walked <u>7233.6 ft</u>
Step-by-step explanation:
13.7 miles ÷ 10 = 1.37 miles
1 mile = 5280 ft
5280 x 1.37 = 7233.6 ft (or 7234 if rounded to the nearest ft)
