Answer:
Putting the value in x = 2 , y =4 in 2x - 2y we get,
2 × 2 - 4× 2= 4-8 = -4
Putting the value in z = 3 in z - 5 we get,
z - 5 = 3 - 5 = -2
Answer:
A) 6.0
Step-by-step explanation:
First, total amount of hours, since average is sum of the numbers by how many numbers there is.
Day 1=8x2 hr
Day 2=6x1 hr
Day 3=4x2 hr
which is, 16+6+8=30
then divide 30 by how many days there is, which is 5 days.
30/5=6
( x² - 1 ) / ( x² + 5 x + 4 ) < 0
x² + 5 x + 4 = x² + 4 x + x + 4 = x ( x + 4 ) + ( x + 4 ) = ( x + 4 ) ( x + 1 )
Therefore:
( x - 1 ) ( x + 1 ) / ( x + 4 ) ( x + 1 ) < 0
( x -1 ) / ( x + 4 ) < 0
1.
x - 1 > 0 and x + 4 < 0
x > 1 and x < - 4 ( not possible )
2.
x - 1 < 0 and x + 4 > 0
x < 1 and x > - 4
Answer: x ∈ ( - 4, 1 ).
I think it’s 162000 because 5.4 * 10 ^4 = 54,000 in standard form and 54,000 * 3 = 162,000