Answer:
x=14
Step-by-step explanation:
x+7=21
x=14
Answer:
1/3
Step-by-step explanation:
6s+4d=$53
4s+6d=$47
Multiply 6 in the first equation which is
36s+24d=$318
Multiply -4 in the second equation which is
-16s-24d=$-188
Then..
36s+24d=$318
-16s-24d=$-188
You cancel out the -24d and +24d
36s=$318
-16s=$-188
Do the math..
20s=$130
Divide 20 by both sides and answer...
s=$6.5
A door alarm works in 72 out of 100 cases.
surveillance camera works in 68 out of 100 cases.
The probability that method A is used = 72/100
The probability that method B is used = 68/100
Since both method are used we find the probability of A and B
Probability ( A and B) =
* 
=