X = low-energy lamp
y = high-energy lamp
1) 4x + 5y
2) 120= 4x + 5y
To do that you'll need the mean and standard deviation of all the scores. Can you provide this info?
For example: Supposing that the mean of these scores were 52 and the standard deviation 3. You'd need to find the "z-score" of 57 in this case.
57 - 52
It is z = ------------ , or z = 5/3, or z = 1.67.
3
Find the area to the left of z = 1.67. Multiply that area by 100% to find the percentile rank of the score 57.
The total cost was 116% of the original bill;
Original bill was;
= <span>$22.5</span>
Answer:
A) 
B) 
Step-by-step explanation:
A) You can add these expression because they contain the same square root:
B) Same as above:
2x - z = 4
6x - 5z = 18
3z - 2w = -18
If u want me to solve them it’s
1. X = -2y + 12
2. x = 10 - 4/3y | for y, y = 15/2 - 3/4x
3. x = 2+ 1/2z | for z , z = -4 + 2x
4. x = 3 + 5/6z | for z , z = - 18/5 + 6/5x
5. W = -3/2x + 13/2 | for x , x = -2/3w + 13/3
6. x = -5w + 13 | w = -1/5x + 13/5
