I think it is something
Question #4
1 answer:
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Step-by-step explanation:
- 1
vector AB(3-(-6); 5-7)
vector AB(9;-2)
AB= =
- 2
M is the midpoint of AB
we have B(-5;10) and M(1;7)
let A(x;y)
(x-5)/2 = 1 ⇒ x-5 = 2⇒ x = 7
(10=y)/2 = 7⇒ 10+y = 14 ⇒y= 4
so : A(7;4)
- 3
the center of the circle is the midponit of the line joining both ends of the diameter
let A(x;y) be the other end
(-2+x)/2 = 2 ⇒ -2+x = 4⇒ x= 6
(5=y) = -1 ⇒ 5+y = -2 ⇒ y= -7
so the coordinates of the other end are (6; -7)
- 4
A,B and C are collinear such as AB=BC so b is the midpoint of AC
(-5+1)/2 = y ⇒ y = -4/2 ⇒ y = -2
((-3=x)/2 = 7 ⇒ -3+x = 14 ⇒ x = 17
so x= 17 and y = -2
Try this solution:
let the unknown two-digits number be 'xy'.
Then it is possible to write any two-digit number as 10x+y, where x - the tens digit and y - the unit digit.
Using the rule described above the phrase 'the tens digit of a number is twice the units digit' may be written as x=2y.
Using the same rule the phrase 'if the digits are reversed, the new number is 36 is less than the original number' may be written as (10x+y)-(10y+x)=36.
These two equations may be resolved as system of two equations:
Check: the original number is 84, the new number is 48; difference is 84-48=36.
answer: 84
let the unknown two-digits number be 'xy'.
Then it is possible to write any two-digit number as 10x+y, where x - the tens digit and y - the unit digit.
Using the rule described above the phrase 'the tens digit of a number is twice the units digit' may be written as x=2y.
Using the same rule the phrase 'if the digits are reversed, the new number is 36 is less than the original number' may be written as (10x+y)-(10y+x)=36.
These two equations may be resolved as system of two equations:
Check: the original number is 84, the new number is 48; difference is 84-48=36.
answer: 84