What number is the opposite from 6.8 A. -6.8 B. 8.6 C. 68 D. -8.6
1 answer:
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Answer: option A and D results in 3 significant figures.
Step-by-step explanation:
A.
The number 17.6 has three significant figures.
B.
The number 119.25 has 5 significant figures
C.
The number of 19.83 has 4 significant figures.
D.
The number of 25.5 has 3 significant figures.
Hence, option A and D results in 3 significant figures.
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)
- $32.40 for 210 minutes
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
The solution of the system of equations; and <em>x</em> = 4, represented on the graph is the point (4, 1)
The graphs are straight line graphs that can be represented with linear functions.
The points on the graph with blue line are; (2, 0), (0, -1)
The slope, <em>m</em>, is therefore;
m = (0 - (-1))/(2 - 0) = 0.5
From the point, (2, 0), we have;
y = 0.5•(x - 2) = 0.5•x - 1
y = 0.5•x - 1...(1)
The equation of the graph that is constructed with red line is x = 4...(2)
The solution is given by equation (1) when<em> </em><em>x </em>= 4 as follows;
- On the blue line, <em>y</em> = 0.5•x - 1
- On the red line, <em>x </em>= 4
The solution satisfies both lines, and it is the point of intersection. At the solution, therefore;
y = 0.5•x - 1 and <em>x</em> = 4
Which gives;
y = 0.5 × 4 - 1 = 1
At the solution, <em>x </em>= 4, and <em>y </em>= 1, which gives the point, (4, 1)
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