Answer: Choice B
(-2, 5)
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Explanation:
The original system is

Multiply both sides of the second equation by 3. Doing so leads to this updated system of equations

Now add straight down
The x terms add to -4x+3x = -1x = -x
The y terms add to 3y+(-3y) = 0y = 0
The terms on the right hand sides add to 23+(-21) = 2
We end up with the equation -x = 2 which solves to x = -2
Now use this to find y. You can pick any equation with x,y in it
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-4x+3y = 23
-4(-2)+3y = 23
8+3y = 23
3y = 23-8
3y = 15
y = 15/3
y = 5
Or
x-y = -7
-2-y = -7
-y = -7+2
y = -5
y = 5
Either way, we get the same y value.
So that's why the solution is (x,y) = (-2, 5)
Answer:
1500 students
600 boys
Step-by-step explanation:
40% are boys, so 60% are girls.
Writing a proportion:
900 / 60% = x / 100%
x = 1500
There are 1500 students in the school, which means there are 600 boys in the school.
Answer:
-9,4
Step-by-step explanation:
Slope for (x₁, y₁) and (x₂, y₂): (-3, 0) and (2, 7)
Slope: (y₂ -y₁) / (x₂ -x₁)
Slope: ( 7 - 0) / (2 - -3) = 7/(2 + 3)
<span>Slope = 7/5
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The answer would be B. As you can see Angle A and angle B are connected by that line and together they would equal 90 degrees like on the other side of line AB.