Answer:
wow
Step-by-step explanation:
I:2x – y + z = 7
II:x + 2y – 5z = -1
III:x – y = 6
you can first use III and substitute x or y to eliminate it in I and II (in this case x):
III: x=6+y
-> substitute x in I and II:
I': 2*(6+y)-y+z=7
12+2y-y+z=7
y+z=-5
II':(6+y)+2y-5z=-1
3y+6-5z=-1
3y-5z=-7
then you can subtract II' from 3*I' to eliminate y:
3*I'=3y+3z=-15
3*I'-II':
3y+3z-(3y-5z)=-15-(-7)
8z=-8
z=-1
insert z in II' to calculate y:
3y-5z=-7
3y+5=-7
3y=-12
y=-4
insert y into III to calculate x:
x-(-4)=6
x+4=6
x=2
so the solution is
x=2
y=-4
z=-1
80% is the same as 4/5, so 4/5 of the class= 20. That means that if there was a picture, 4 parts would be shaded, and 1 would not. 1/4 of 20 is 5, so 1 part= 5 people. 5 x 5 = 25. 25 is the answer. :)
Answer:
B
Step-by-step explanation:
The circle has to be hallow in order for it to be greater than or less than. The arrow is going below 4 because the circle is on 4 and the arrow is pointing to the left side.
Given : A rectangular picture frame has a perimeter of 52 inches. The height of the frame is 12 inches.
To Find : The width of the frame .
Solution : Let us take the width of the frame be x . So , we know the formula to find the perimeter of rectangle as ;
Where , l is the length of the rectangle and b is the breadth of the rectangle .
⇒ Perimeter = 2 ( l + b ) .
⇒ 52 in. = 2 ( 12 + x ) in.
⇒ 52 in.= 24in. + 2x .
⇒ 2x =( 52 - 24 ) in
⇒ 2x = 28 in.
⇒ x = 28/2 in.
⇒ x = 14 in.
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