Let the cost of gasoline in the year 2000 be represented b the equation
y = a + b*x
where
x = months, counted from January
y = cost, dollars
The given data in the table is
Month: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
x, months: 1 2 3 4 5 6 7 8 9 10 11 12
y, dollars: --- --- --- --- 1.76 2.13 --- --- --- --- --- ---
When x = 5, y = 1.76.
Therefore
a + 5b = 1.76 (1)
When x = 6, y = 2.13
Therefore
a + 6b = 2.13 (2)
Subtract equation (1) from (2).
a + 6b - (a + 5b) = 2.13 - 1.76
b = 0.37
From (1), obtain
a = 1.76 - 5b
= 1.76 - 5*0.37
= -0.09
The required equation is
y = 0.37x - 0.09
The graph shows the line, with the given data for May and June.
Answer: D. y = 0.37x - 0.09
Equation 1) 3x + 2y - 5z = 3
Equation 2) 4x - 2y - 3z = -10
Equation 3) 5x - 2y - 2z = -11
Add equation 1 with equation 2.
Equation 4) 7x - 8z = 7
Then subtract equation 3 from equation 2.
Equation 5) -x -z = 1
Multiply all of equation 5 with 7.
5) -7x - 7z = 7
4) 7x - 8z = 7
Add equations together.
z = 14
Plug in 14 for z in equation 4.
7x - 8z = 7
7x - 8(14) = 7
7x - 112 = 7
7x = 119
x = 17
Plug in 17 for x in equation 1, and 14 for z.
1) 3x + 2y - 5z = 3
3(17) + 2y - 5(14) = 3
51 + 2y - 70 = 3
2y - 19 = 3
2y = 22
y = 11
So, x = 17, y = 11, and z = 14
~Hope I helped!~
Answer:
see explanation
Step-by-step explanation:
Given
tan a =
= 
We require the hypotenuse h
Using Pythagoras' identity
h² = 9² + 40² = 81 + 1600 = 1681 ( take square root of both sides )
h =
= 41 , thus
sin a =
= 
cos a =
= 