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:
6 weeks 27kilo
12 weeks 54 kilo
Step-by-step explanation:
4.5*12=54
4.5*6=27
Answer:
72°
Step-by-step explanation:
Angle 8 and angle 14 are corresponding angles.
∠8=∠14
72=∠14
Answer:
60cm
Step-by-step explanation:
perimeter of a square=4L
192cm=4L
L=48cm
Dilated by ratio 0.25
1 : 0.25 = 48 : 12
New length = 48+12 = 60cm.
Answer: He earned 43,344 a year and earned and earned 3612 a month