Distributive property
12-3x-13 = 0
Combine like terms
-1-3x = 0
-3x = 1
Divide by -3
x = -1/3
Answer:
532
Step-by-step explanation:
The score that represents the top 20% = A score = 80%
Z score for 80% percentile = 0.842
We solve using the z score formula
z = (x-μ)/σ, where
x is the raw score = ??
μ is the population mean = 490
and σ is the population standard deviation = 50
Hence:
0.842 = x - 490/50
Cross Multiply
0.842 × 50 = x - 490
x = 0.842 × 50 + 490
x = 42.1 + 490
x = 532.1
Approximately = 532
Therefore, the test score = 532
Answer:
The cost of 1 ruler and 1 pencil are $0.35 and $0.25 respectively,
Step-by-step explanation:
Let the cost of 1 ruler be x
Let the cost of 1 pencil be y
Cost of 4 rulers = 4x
Cost of 3 rulers = 3x
Cost of 3 pencils = 3y
Cost of 4 pencils = 4y
We are given that Four rulers and three pencils cost £2.15
4x+3y=2.15 ---- Black line
We are also given that Three rulers and four pencils cost £2.05
3x+4y=2.05 --- Red line
Plot the lines on the graph
Point of Intersection of lines is (0.35,0.25)
Cost of a ruler = $0.35
Cost of a pencil = $0.25
Hence The cost of 1 ruler and 1 pencil are $0.35 and $0.25 respectively,
3 seconds
0= -16t^2+144
-144/-16=9
9=t^2
Sq rt of 9 is 3
y is part of a right angle on line AB
a right angle = 90 degrees
90-47 = 43 degrees
y = 43 degrees
a straight line = 180 degrees
180-47 = 133 degrees
x = 133 degrees