Answer:
= 9
Step-by-step explanation:
Given that,
Asn expression : 
We need to evaluate the above expression.
We know that, 
So,

or

So, the value of
is 9. Hence, the correct option is (b).
Answer:
x=1/2, y=2;
Step-by-step explanation:
First pair:
2x-5y =-9
4x+5y=12
Add them together:
6x=3
x = 1/2
2(1/2) - 5y =-9
1-5y = -9
1+9=5y
y=10/5=2
It will take him 120 mins as he runs 8 minute miles
Answer:
45 people are members at the tennis club
Step-by-step explanation:
Let the number of people in the tennis club be denoted as "x".
Since each of them donated $12.45, then total donated = 12.45x
Since they had $50.25 left over after paying the cost of $510 for the ball, then;
12.45x - 510 = 50.25
12.45x = 510 + 50.25
12.45x = 560.25
x = 560.25/12.45
x = 45