Answer:
xxxxxxxx
Step-by-step explanation:
x
9514 1404 393
Answer:
(t, u, w) = (1, -2, -2)
Step-by-step explanation:
A graphing calculator makes short work of this, giving the solution as ...
(t, u, w) = (1, -2, -2)
__
There are many ways to solve this "by hand." Here's one of them.
Add the first and third equations. Their sum is ...
-3t +4w = -11 . . . . . [eq4]
Add this to twice the second equation. That sum is ...
(-3t +4w) +2(-4t -2w) = (-11) +2(0)
-11t = -11
t = 1
Substituting this into the second equation gives ...
-4(1) -2w = 0
w +2 = 0 . . . . divide by -2
w = -2 . . . . add -2
Substituting for t in the third equation lets us find u.
2(1) -2u = 6
-1 +u = -3 . . . . . divide by -2
u = -2 . . . . add 1
The solution is (t, u, w) = (1, -2, -2).
Answer:
$21.2
Step-by-step explanation:
From the problem given, we express them as algebra so that we can easily solve;
the total charge on a call greater than 120min is given as;
120x + y(n - 120) = total cost of call
where n is the number of minutes which is greater than 120;
- Ethan paid $26.80 for 175 mins
n = 175min here;
120x + y(175 - 120) = 26.80
120x + 55y = 26.80 ----- (I)
n = 210min
120x + y(210 - 120) = 32.4
120x + 90y = 32.4 ----- (II)
Now let us solve both equations for y and x;
120x + 55y = 26.80 ----- (I)
120x + 90y = 32.4 ----- (II)
subtract the two equations;
90y - 55y = 32.4 - 26.8
35y = 5.6
y =
= 0.16cents
then x;
120x = 26.8 - 55y from equation I
120x = 26.8 - 55(0.16)
120x = 18
x =
= 0.15cents
Find the cost of 140min of talk time;
n =140min;
= 120(0.15) + 0.16(140 - 120)
= 18 + 0.16(20)
= 18 + 3.2
= $21.2
Answer:
1+1+2
Step-by-step explanation:
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