Carrie gets 5 points for each answer and has already earned 10 points of extra credit she needs at least 77 to pass
1 answer:
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2 Answers:
- B) The lines are parallel
- C) The lines have the same slope.
Parallel lines always have equal slope, but different y intercepts.
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Explanation:
Let's solve the second equation for y
3y - x = -7
3y = -7+x
3y = x-7
y = (x-7)/3
y = x/3 - 7/3
y = (1/3)x - 7/3
The equation is in y = mx+b form with m = 1/3 as the slope and b = -7/3 as the y intercept. We see that the first equation, where y was already isolated, also has a slope of m = 1/3. The two equations of this system have the same slope. Choice C is one of the answers.
However, they don't have the same y intercept. The first equation has y intercept b = -4, while the second has b = -7/3. This means that they do not represent the same line. They need to have identical slopes, and identical y intercepts (though the slope can be different from the y intercept of course) in order to have identical lines. So we can rule out choice D and E because of this.
Because the two equations have the same slope, but different y intercepts, this means the lines are parallel. Choice B is the other answer.
Parallel lines never touch or intersect, which in turn means there is no solution point. A solution point is where the lines cross. We can rule out choice A.
I recommend using your graphing calculator, Desmos, GeoGebra, or any graphing tool (on your computer or online) to graph each equation given. You should see two parallel lines forming. I used GeoGebra to make the graph shown below.
The cost of pen and pencils are related to the number that can be bought
with a given amount of money.
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Reasons:
The given parameters are;
If the number number of pens and pencils James buys = 3 pens and 2 pencils, the amount James will have left = $2
If the number of pens and pencils James buys = 2 pens and 3 pencils, the amount James will have left = $6
The amount of money Judith has = The amount of money with James
The number of pens and pencil James and Judith can buy = 6 pens and 6 pencils
The cost of one pen = a
The cost of one pencil = b
Required:
To find the ordered pair (a, b)
Solution:
Let <em>X</em> represent the initial amount of money James has, we get;
X - (3·a + 2·b) = 2...(1)
X - (2·a + 3·b) = 6...(2)
2·X = 6·a + 6·b...(3)
Therefore;
X = (6·a + 6·b) ÷ 2 = 3·a + 3·b
Which from equation (1) gives;
3·a + 3·b - (3·a + 2·b) = 2
3·a + 3·b - 3·a - 2·b = 2
3·b - 2·b = 2
b = 2
Subtracting equation (1) from equation (2) gives;
(X - (2·a + 3·b)) - (X - (3·a + 2·b)) = 6 - 2 = 4
-2·a - 3·b + 3·a + 2·b = 4
a - b = 4
a = 4 + b
∴ a = 4 + 2 = 6
a = 6
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Learn more about word problems and simultaneous equations here: