Let the original number be x.
Acc. to the question,
2x+1616=(2/5)x
or, 10x+8080=2x
or, 10x-2x= -8080
or, 8x= -8080
or, x= -8080/8
or, x = -1010
Therefore, the original number is -1010
Answer:
11 mm
Step-by-step explanation:
An octagon has 8 sides. This mean that we do 88 divided by 8 to get the length of each side which is 11 mm.
<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>
25/5 = 5
and also
15/3 = 5
so
(3x+ 8)/5 = 4
3x + 8 = 20
3x = 12
x = 12/3
x = 4
answer is x = 4
