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
Sonja [21]
3 years ago
10

Let x^2+15x=49

Mathematics
2 answers:
-BARSIC- [3]3 years ago
8 0

The correct answer is:

x^2 + 15x + 56.25 = 105.25

i just finished the test and these were the correct answers :)

Slav-nsk [51]3 years ago
3 0
<span>x^2 + 15x + 56.25 = 105.25

    "Completing the square" is one of many different techniques for solving a quadratic equation. What you do is add a constant to both sides of the equation such that the lefthand side can be factored into the form a(x+d)^2. For instance, squaring (X+D) = X^2 + 2DX + D^2. Notice the 2DX term. That is the same term as the 15x term in the problem. So 2D = 15, D = 7.5. And D^2 = 7.5^2 = 56.25.
So we have
 x^2 + 15x + 56.25 = 49 + 56.25
 Which is
 x^2 + 15x + 56.25 = 105.25
  Which is the answer desired.

   Now the rest of this is going beyond the answer. Namely, it's answering the question "Why does complementing the square help?" Well, we know that the left hand side of the equation can now be written as
 (x+7.5)^2 = 105.25

   Now take the square root of each side
 (x+7.5) = sqrt(105.25)

   And let's use both the positive and negative square roots.
So x+7.5 = 10.25914226
 and
 x+7.5 = -10.25914226

   And let's find X.
 x+7.5 = 10.25914226
 x = 2.759142264

   x+7.5 = -10.25914226
 x = -17.75914226

   So the roots for x^2 + 15x - 49 is 2.759142264, and -17.75914226</span>
You might be interested in
When 0.3(4x - 8) - 0.5(2.4x + 4) is simplified what is the resulting expression?
LUCKY_DIMON [66]
0.3(4x-8)-0.5(2.4x+4)
1.2x-2.4-1.2x+2
x-0.4
4 0
3 years ago
Which equation has no solution?
Dmitry [639]

Answer:

A for sure

Step-by-step explanation:

4 0
3 years ago
How do you write 6.0 as a percentage?
FrozenT [24]
Im pretty sure that it would be 600%. If it was 600% that would be 600 over 100 which would be 6
6 0
3 years ago
An rectangular water tank has a base area of 56 sq. ft. and a height of 4 ft. Find its volume in cubic feet.
ira [324]

Answer: 224 cubic feet

Step-by-step explanation: If the base of the tank is 56 sq feet in<u> area </u> then the dimensions could be, (2,28) (4,14) (7,8) for example. However, it doesn't really matter. It's only important that the information we know is that it is area and there are two dimensions. Since volume is determined by base x width x height, we do 56 x 4. Or using one of the factored pairs that works, for example, 8 x 7 x 4 = 224.

7 0
2 years ago
Which operation should be performed first for calculations involving more than one arithmetic operation?
liq [111]
Operations are performed according to the Order of Operations. Sometimes the mnemonic PEMDAS or BIDMAS is used to remind you what the order is.

P/B - parentheses/brackets. The content of these is evaluated first.

E/I - exponents/indices. Exponentiation is done first, right to left: a^b^c = a^(b^c).

MD/DM - multiplication and division are done in order of appearance, left to right. Each has equal priority, neither is done before the other unless it appears in the expression first. a/bc = (a/b)c. ab/c = (ab)/c

AS - addition and subtraction are done in order of appearance, left to right. Each has equal priority.
_____
When functions are involved (sin( ), log( ), sqrt( ), for example), their arguments are evaluated according to the order of operations, then the function is evaluated, then the remainder of the operations are performed. For example, sin(a)^2 = (sin(a))^2. Sometimes, this is written sin^2(a).

When functions are written without parentheses around their arguments, it must be assumed that the function only applies to the first entity following the function name. log ab+c/d = (log(a)*b)+(c/d), for example, or √3x = (√3)x.
6 0
3 years ago
Other questions:
  • Work out the area of a parallelogram of base 5m and height 3m
    15·1 answer
  • (4.1.4) Let X and Y be Bernoulli random variables. Let Z = X + Y. a. Show that if X and Y cannot both be equal to 1, then Z is a
    8·1 answer
  • If 1 hour is 60 minutes then what will 5 hours equal
    6·2 answers
  • What is the range of the function f(x)=3x-4 when the domain is{2,4,6}?
    12·1 answer
  • A boat travels 8 km upstream and 8 km back. The time for the round trip is 2 hrs. The speed of the stream is 4 ​km/hr. What is t
    6·1 answer
  • Resuelve la ecuación de la recta que pasa por el punto A (2, – 4) y tiene una pendiente de – 1/3. Utiliza la Ecuación de la Rect
    9·1 answer
  • Explain the relationship of the meaning of the word isometric to the properties of an isometric or rigid transformation
    13·1 answer
  • Math Algebra 1 Honors Unit 4 that's what it is ​
    13·1 answer
  • A lifeguard received 15 hours of first aid training and 10 hours of CPR training. What is the ratio of hours of CPR training to
    12·1 answer
  • 2-61. One of Teddy's jobs at home is to pump gas for his family's sedan and truck. When he fills up the sedan with 12 gallons of
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!