Answer:6z
Step-by-step explanation:
4z+2z=6z
Step 1. Multiply first equation with -3 and the second one with 2. You'll get:

Step 2. Add both equations together. You'll get:

, which gives x = -2
Step 3. Replace x = -2 in the first equation and calculate y.

The solution is: x=-2, y=5
Answer: £ 8
Step-by-step explanation:
Total hours Lena works from Monday to Friday = 34 hours
Hours she works on Saturdays = 4
Overtime rate of Saturday = 1.5 times her normal rate
Let x be the normal rate.
Then , Her total earning = 
Since her total earnings for week = £ 320
So,

Thus, her normal rate of pay per hour = £ 8
Answer:
The 10% condition would not apply here
Explanation:
The 10% condition is the recommended size of sample from the population to get a non biased result. The 10% condition requires that the sample be not more than 10% of the population.
Tossing a coin is an example of a Bernoulli trial. A Bernoulli trial is one that has two possible outcomes, this face of the coin or the other face of the coin. The 10% condition does not apply to Bernoulli trials that are independent events.
Therefore the 10% condition would not apply here because tossing a coin is an an independent event. An independent event is one with replacement.