<em>Greetings from Brasil...</em>
According to the statement of the question, we can assemble the following system of equation:
X · Y = - 2 i
X + Y = 7 ii
isolating X from i and replacing in ii:
X · Y = - 2
X = - 2/Y
X + Y = 7
(- 2/Y) + Y = 7 <em>multiplying everything by Y</em>
(- 2Y/Y) + Y·Y = 7·Y
- 2 + Y² = 7X <em> rearranging everything</em>
Y² - 7X - 2 = 0 <em>2nd degree equation</em>
Δ = b² - 4·a·c
Δ = (- 7)² - 4·1·(- 2)
Δ = 49 + 8
Δ = 57
X = (- b ± √Δ)/2a
X' = (- (- 7) ± √57)/2·1
X' = (7 + √57)/2
X' = (7 - √57)/2
So, the numbers are:
<h2>
(7 + √57)/2</h2>
and
<h2>
(7 - √57)/2</h2>
30000mm÷10=3000cm
3000cm÷100=30m
Answer: 30m
<h3>Answer :- </h3>
- Let the three consecutive numbers be x -2 , x and x + 2
- Their sum = ( x - 2 ) + ( x + 2 ) = 3x
- This is the given equal to 54
- 3x = 54 or x = 54/3
- x = 18
<em>Thus </em><em>,</em><em> </em><em>the </em><em>required </em><em>numbers </em><em>are </em><em>1</em><em>6</em><em> </em><em>,</em><em> </em><em>1</em><em>8</em><em> </em><em>,</em><em> </em><em>2</em><em>0</em><em> </em>
Answer:
x1=-4/5, x2=18/5 and x3=7/5
Step-by-step explanation:
![\left[\begin{array}{ccc|c}1&0&-3&-5\\3&1&2&4\\2&2&1&7\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%260%26-3%26-5%5C%5C3%261%262%264%5C%5C2%262%261%267%5Cend%7Barray%7D%5Cright%5D)
you can do linear combination between the rows:
2nd row=R2-3R1 and 3th row=R3-2R1
![\left[\begin{array}{ccc|c}1&0&-3&-5\\0&1&11&19\\0&2&7&17\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%260%26-3%26-5%5C%5C0%261%2611%2619%5C%5C0%262%267%2617%5Cend%7Barray%7D%5Cright%5D)
3th row=(3R2-R3)/15
![\left[\begin{array}{ccc|c}1&0&-3&-5\\0&1&11&19\\0&0&1&\frac{7}{5} \end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%260%26-3%26-5%5C%5C0%261%2611%2619%5C%5C0%260%261%26%5Cfrac%7B7%7D%7B5%7D%20%5Cend%7Barray%7D%5Cright%5D)
1st row=R1+3R3 and R2-11R3
![\left[\begin{array}{ccc|c}1&0&0&-4/5 \\0&1&0&18/5 \\0&0&1&7/5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%260%260%26-4%2F5%20%5C%5C0%261%260%2618%2F5%20%5C%5C0%260%261%267%2F5%5Cend%7Barray%7D%5Cright%5D)
x1=-4/5, x2=18/5 and x3=7/5
Answer:
88.5
Step-by-step explanation:
(90+82+81+2x)/5=86
90+82+81+2x=430
2x=177
x=88.5
