Answer:the third option is correct
Step-by-step explanation:
The system of equations are
y = 2x^2 - 5x - 7 - - - - - - - - - - -1
y = 2x + 2 - - - - - - - - - - - - - 2
We would equate equation 1 and equation 2. It becomes
2x^2 - 5x - 7 = 2x + 2
2x^2 - 5x - 2x - 7 - 2 = 0
2x^2 - 7x - 9 = 0
We would find two numbers such that their sum or difference is -7x and their product is - 18x^2. The two numbers are 2x and - 9x. Therefore
2x^2 + 2x - 9x - 9 = 0
2x(x + 1) - 9(x + 1) = 0
2x - 9 = 0 or x + 1 = 0
2x = 9 or x = - 1
x = 9/2 = 4.5
Substituting x = 4.5 or x = -1 into equation 2, it becomes
y = 2 × 4.5 + 2 or y = 2 × - 1 + 2
y = 11 or y = 0
Therefore, the solutions are
(4.5, 11) (- 1, 0)
Answer:
$150
Step-by-step explanation:
First use a proportion to find the answer:
40/100=60/x
Now we solve for x
60*100=6,000
6,000 divided by 40= 150
x=150
Therefore the answer is $150
Here's the link for the image: http://assets.openstudy.com/updates/attachments/5507589de4b01982d6668698-winsteria-1426544809579-ms_......
The correct is this one: "d. 3(9) + 7(5)." Lisa divided the irregular polygon into 2 rectangles with a line. The <span> expression that can be used to find the area of the irregular polygon is 3(9) + 7(5). That will give you the total are of the two rectangles.</span>
<h3>Given</h3>
z = 3
2y +z = 1
2x +3y +2z = 13
<h3>Find</h3>
x, y, z
<h3>Solution</h3>
... z = 3 is given
Substitute that into the second equation.
... 2y + 3 = 1
... 2y = -2 . . . . . subtract 3
... y = -1 . . . . . . . divide by the coefficient of y
Substitute these two solutions into the third equation.
... 2x +3(-1) +2(3) = 13
... 2x = 10 . . . . . . . . . . . . collect terms, subtract 3
... x = 5 . . . . . . . . . . . . . . divide by the coefficient of x
The variable values are: x = 5, y = -1, z = 3
