What number must you add to complete the square? x2 + 8x = 11
1 answer:
Answer:
16
Step-by-step explanation:
The number to add on both sides to complete the square is the square of the numerical coefficient that accompanies the term in "x", divided by 2.
That is in our case:
Therefore:
That way the left hand side of the equation becomes the perfect square of the binomial: (x+4).
You can also prove that such is correct by developing the square of the binomial:
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Answer:
1. The equation is solved by the graphed systems of equations is:
Third option: 7x + 3 = x − 3
2. The solution to the system is:
Fourth option: (3,-1)
3. The graph of the system y = −2x + 3 and 2x + 4y = 8 is:
Third option: Line through point (0, 3) and (1, 1). Line through (0, 2) and (4, 0).
4. The solution to the system is:
Second option: Infinite solutions.
5. Bill will have read the same amount of books as Mandy in:
Fourth option: December
Step-by-step explanation:
Question 1. What equation is solved by the graphed systems of equations?
Two linear equations that intersect at the point (-1, -4)=(x,y)→x=-1, y=-4
a. 7x + 3 = x + 3
Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:
7x+3-x=x+3-x
6x+3=3
Subtracting 3 both sides of the equation:
6x+3-3=3-3
6x=0
Dividing both sides of the equation by 6:
6x/6=0/6
Dividing:
x=0 different to the intersection at x=-1, then this is not the equation.
b. 7x − 3 = x − 3
Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:
7x-3-x=x-3-x
6x-3=-3
Adding 3 both sides of the equation:
6x-3+3=-3+3
6x=0
Dividing both sides of the equation by 6:
6x/6=0/6
Dividing:
x=0 different to the intersection at x=-1, then this is not the equation.
c. 7x + 3 = x − 3
Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:
7x+3-x=x-3-x
6x+3=-3
Subtracting 3 both sides of the equation:
6x+3-3=-3-3
6x=-6
Dividing both sides of the equation by 6:
6x/6=-6/6
Dividing:
x=-1 equal to the intersection at x=-1, then this is the equation.
d. 7x − 3 = x + 3
Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:
7x-3-x=x+3-x
6x-3=3
Adding 3 both sides of the equation:
6x-3+3=3+3
6x=6
Dividing both sides of the equation by 6:
6x/6=6/6
Dividing:
x=1 different to the intersection at x=-1, then this is not the equation.
Question 2 (Multiple Choice Worth 2 points) (06.03) Solve the system 2x + 3y = 3 and 3x − 2y = 11 by using graph paper or graphing technology. What is the solution to the system?
The solution to the system is (3, -1) Fourth option
Please, see the attached graph.
Question 3 (Multiple Choice Worth 2 points) (06.03) What is the graph of the system y = −2x + 3 and 2x + 4y = 8?
Third option: Line through point (0, 3) and (1, 1). Line through (0, 2) and (4, 0).
Please, see the attached graph.
Question 4 (Multiple Choice Worth 2 points) (06.03) Solve the system y = 3x + 2 and 3y = 9x + 6 by using graph paper or graphing technology. What is the solution to the system?
Second option: Infinite solutions.
Please, see the attached graph.
Question 5 (Multiple Choice Worth 2 points) (06.03) At the end of April, Mandy told Bill that she has read 16 books this year and reads 2 books each month. Bill wants to catch up to Mandy. He tracks his book reading with a table on his door. Using his table below, what month will Bill have read the same amount of books as Mandy?
Bill
Month Books
May 4
June 8
July 12
August 16
September 20
October 24
November 28
December 32
Books read by Mandy: y=16+2x
Numbers of months since april: x
May: x=1→y=16+2(1)=16+2→y=18 different to 4 (books read by Bill)
June: x=2→y=16+2(2)=16+4→y=20 different to 8 (books read by Bill)
July: x=3→y=16+2(3)=16+6→y=22 different to 12 (books read by Bill)
September: x=5→y=16+2(5)=16+10→y=26 different to 20 (books read by Bill)
October: x=6→y=16+2(6)=16+12→y=28 different to 24 (books read by Bill)
November: x=7→y=16+2(7)=16+14→y=30 different to 28 (books read by Bill)
December: x=8→y=16+2(8)=16+16→y=32 equal to 32 (books read by Bill)
Answer. Fourth option: December
