Answer:
$.80 or 80¢
Step-by-step explanation:
US Coin Denominations are as follows:
Quarters: $.25
Dime: $.10
Nickel: $.05
Penny: $.01
We can now use the following
(1*25)+(5*5)+(3*10)=80
So first y = 3.50 + 15 = 18.5
Next 2x + y = -1.5
2x = -1.5 -y
2x = -1.5 - 18.5 = -20
x = -20/2 = -10
So
x = -10
y = 18.5
Answer:
(5×6)=30×7=140 the answer is 140
Abswer is here
100.571429
Answer:
5 hours
Step-by-step explanation:
Let s and w represent hours spent traveling south and west, respectively. The problem statement tells us ...
s + w = 8 . . . . . . total trip time
344s + 351w = 2773 . . . . total mileage (using d = s·t)
By Cramer's rule, we can find the value of s as ...
s = (1(2773) -351(8))/(1(344) -351(1)) = -35/-7 = 5
The plane was heading south for 5 hours.
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<em>Comment on Cramer's rule</em>
For the equations ...
ax +by = c
dx +ey = f
The solution for x can be found to be ...
x = (bf-ec)/(bd-ea)
Similarly, the solution for y is ...
y = (cd-fa)/(bd-ea)
