Answer:
110 test
Step-by-step explanation:
Let
x ----> the number of packet of 10 test
y ----> the total cost
we know that
The number of packet of 10 test purchase multiplied by $11 plus the enrollment fee of $30 must be equal to $151
so
The linear equation that represent this scenario is

we have

substitute

Solve for x
subtract 30 both sides


Divide by 11 both sides

The number of packets purchase was 11
To find out the number of test, multiply the number of packets by 10

From the graph of the given function , the value of f(1) = -1.
As given in the question,
From the graph of the given function,
Two coordinates from the graph are as follow:
( x₁ , y₁) = (1, -1)
( x₂ , y₂ ) = ( 0, -3 )
Equation of the line representing the function is given by:
(y - y₁) /(x-x₁) = ( y₂ -y₁)/ (x₂ -x₁)
⇒(y +1)/ (x-1) = (-3 +1)/ (0-1)
⇒ (y +1)/ (x-1) = 2
⇒y +1 = 2x -2
⇒ y = 2x -3
To get the value of x we have,
y = f(x)
⇒f(x) = 2x -3
⇒f(1) = 2(1) -3
⇒f(1) = -1
Therefore, from the graph of the given function , the value of f(1) = -1.
Learn more about graph here
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Answer:
pieces
Step-by-step explanation:
Suppose you have a 7 feet long wood.
You need to find how many
-foot pieces can be cut from this wood.
To find this number of pieces, you have to divide the whole length of the wood by the length of one piece:

1)
I:x-y=-7
II:x+y=7
add both equations together to eliminate y:
x-y+(x+y)=-7+7
2x=0
x=0
insert x=0 into II:
0+y=7
y=7
the solution is (0,7)
2)
I: 3x+y=4
II: 2x+y=5
add I+(-1*II) together to eliminate y:
3x+y+(-2x-y)=4+(-5)
x=-1
insert x=-1 into I:
3*-1+y=4
y=7
the solution is (-1,7)
3)
I: 2e-3f=-9
II: e+3f=18
add both equations together to eliminate f:
2e-3f+(e+3f)=-9+18
3e=9
e=3
insert e=3 into I:
2*3-3f=-9
-3f=-9-6
-3f=-15
3f=15
f=5
the solution is (3,5)
4)
I: 3d-e=7
II: d+e=5
add both equations together to eliminate e:
3d-e+(d+e)=7+5
4d=12
d=3
insert d=3 into II:
3+e=5
e=2
the solution is (3,2)
5)
I: 8x+y=14
II: 3x+y=4
add I+(-1*II) together to eliminate y
8x+y+(-3x-y)=14-4
5x=10
x=2
insert x=2 into II:
3*2+y=4
y=4-6
y=-2
the solution is (2,-2)
Answer:
$31.8
Step-by-step explanation:
Assuming the 6% tax is separate from the $30, we can use this equation:
Total = Cost + Tax (pretty self explanatory)
Method 1
Total = $30 + (6% * $30)
Total = $30 + $1.8
Total = $31.8
Method 2
Total = $30 * 1.06 (The 1 is the original cost, the .06 is the 6% tax)
Total = $31.8