1. They are all round.
2.The kids got each other sick. They were contagious.
3. 15: 15, 30, 45
20: 20, 40, 60, 80
25: 25, 50, 75, 100
The multiples of five will either end in 0 or 5.
is this correct?
a * b = -70
a + b = -9......a = -9 - b
b(-9 - b) = -70
-b^2 - 9b + 70 = 0
(-b + 5)(b + 14) = 0
-b + 5 = 0
5 = b
b + 14 = 0
b = -14
ur numbers are -14 and 5
-14 * 5 = -70
-14 + 5 = -9
Answer:

Step-by-step explanation:
Given
Total = 900
Singing = 600
Dancing = 500
None = 125
Required
Determine the number of students that participate in both
Representing; Singing with S, Dancing with D, Both singing and dancing with B and None with N;
In Set Notation;

Substitute 900 for Total, 600 for S, 500 for D and 125 for N

Open Brackets

Collect Like Terms



Collect Like Terms


Multiply both sides by -1


Reorder

<em>Hence, the number of students that do not participate in both is 325</em>