In 371 ways Mrs. Sullivan choose two students from 27 to help put away calculators at the end of class
Step-by-step explanation:
let us assume that Mrs.Sullivan wants to choose 2 students from a group of 27 students
So ,in the first choice we have 27 students
In the second choice we have 26 choices
So Mrs.Sullivan has = 27 × 26 = 702 ways
But each group repeated twice,in order to avoid that we will divide the answer by 2
so we will write
= 702 ÷ 2 =<u> 351 ways</u>
<u>This method of calculation is called Combination</u>
Answer:
Step-by-step explanation:
First you need to convert it to a linear expression.
3x - y = 4
+3x +3x
-1y = 3x + 4
--- ----- -----
-1 -1 -1
y = -3x -4
6x - 2y = 7
-6x -6x
-2y = -6x + 7
---- ----- -----
-2 -2 -2
y = 3x - 3.5
-3x - 4 = 3x - 3.5
+3x +3x
-4 = 6x - 3.5
+3.5 +3.5
-0.5 = 6x
----- -----
6 6
-0.5
------ = x
6
Answer:
18
Step-by-step explanation:
63/7 = 9
Reduction factor is 9
2x9 = 18
x = 18
Hope that helps
I think its A the first one