Answer:
20
Step-by-step explanation:
Our expression:
2 * (18 + - 8)
Plus then minus (+ -) is the same as just minus ( - )
Some examples:
1 + (+ 1) = 2
1 + (- 1) = 0
1 - (+ 1) = 0
1 - (- 1) = 2
Thus, 18 + - 8 is the same as 18 - 8
2 * (18 + - 8) =
= 2 * (18 - 8) =
= 2* (10) =
= 2 * 10 =
= 20
Answer: 20
Answer:
B and E
Step-by-step explanation:
Answer:
upper right
Step-by-step explanation:
The net for a figure is a representation of all of the figure's faces. The polygons in the net are joined on an edge corresponding to a common edge between the faces they represent.
The given figure is a rectangular prism. Its faces are only rectangles. All nets that have triangles in the net can be eliminated from consideration.
The appropriate choice is the one attached.
Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
The answer is c I might be wrong
