1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
liubo4ka [24]
3 years ago
8

Solve x2 - 4x - 7 = 0 by completing the square. What are the solutions?

Mathematics
1 answer:
Roman55 [17]3 years ago
5 0

Answer:

x= 2 + √11 or x = 2 −√11

Step-by-step explanation:

I am going to complete the square step-by-step.

x² − 4x − 7=0

Step 1: Add 7 to both sides.

x² − 4x − 7+ 7 = 0 + 7

x² − 4x = 7

Step 2: The coefficient of -4x is -4. Let b = -4.

Then we need to add (b/2)² = 4 to both sides to complete the square.

Add 4 to both sides.

x² − 4x + 4 = 7 + 4

x² − 4x + 4 = 11

Step 3: Factor left side.

(x−2)² = 11

Step 4: Take square root.

x − 2 = ±√11

Step 5: Add 2 to both sides.

x − 2 + 2 = 2 ±√11

x = 2 ±√11

x= 2 + √11 or x = 2 −√11

You might be interested in
(a) find parametric equations for the line of intersection of the planes x + y + z = 2 and x + 7y + 7z = 2
nlexa [21]
Direction vector of line of intersection of two planes is the cross product of the normal vectors of the planes, namely
p1: x+y+z=2
p2: x+7y+7z=2

and the corresponding normal vectors are: (equiv. to coeff. of the plane)
n1:<1,1,1>
n2:<1,7,7>

The cross product n1 x n2
vl=
 i  j  l
1 1 1
1 7 7
=<7-7, 1-7, 7-1>
=<0,-6,6>
Simplify by reducing length by a factor of 6
vl=<0,-1,1>

By observing the equations of the two planes, we see that (2,0,0) is a point on the intersection, because this points satisfies both plane equations.

Thus the parametric equation of the line is
L: (2,0,0)+t(0,-1,1)
or
L: x=2, y=-t, z=t

3 0
3 years ago
A diamond shaped sign is a ______ sign
suter [353]

A warning/caution sign?

7 0
3 years ago
According to the order of operations, what operation should be performed first in the expression 8 minus 2 times 2 divided by le
Crank

Answer:

addition

Step-by-step explanation:

in this case its addition , but the only reson it is going first is bc it sin the parenthasies

3 0
3 years ago
Read 2 more answers
Distribute property -3(6+h)
ValentinkaMS [17]

Answer:

Answer: -18 + -3h

More simple: -18 - 3h

Step-by-step explanation:

  1. -3 × 6 = -18
  2. -3 × h = -3h
  3. Put them together: -18 + -3h
5 0
3 years ago
Read 2 more answers
(За + 2b – 7) - (4) — 10)
Sedaia [141]

Answer:=3a+2b−21

Step-by-step explanation:

Let's simplify step-by-step.

3a+2b−7−4−10

=3a+2b+−7+−4+−10

Combine Like Terms:

=3a+2b+−7+−4+−10

=(3a)+(2b)+(−7+−4+−10)

=3a+2b+−21

4 0
3 years ago
Other questions:
  • Find the ordered pairs for the x- and y-intercepts of the equation 5x − 6y = 30 and select the appropriate option below.
    9·2 answers
  • What is the value of n? 9×27+2×31-28=n
    9·2 answers
  • PLEASE HELPPP!!! I will mark brainlist​
    11·2 answers
  • If 9 (x) = – 5x2 – 4x + 19 find f (–3)
    10·1 answer
  • Tomas collects miniature cars. He bought a display case at a cost of $5.95. He also bought 3 miniature cars. If his total cost w
    15·2 answers
  • A store is having a sale on 200 dvd movies.some of the movies are being sold for $10 and some are being sold for $12.if the stor
    15·1 answer
  • there are 20 students in the group , 15 from them are athletes. it is taken for competition 10 students. find the probability th
    13·1 answer
  • .24 repeating as a fraction but the 4 is the only thing repeating
    5·1 answer
  • Plzzzzzzzzzzzzzzzz help me I’ll mark you brainlist
    11·2 answers
  • Lily ran 100 meters in 15 seconds. How long did she take to run 2 meters
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!