Using the dot product:
For any vector x, we have
||x|| = √(x • x)
This means that
||w|| = √(w • w)
… = √((u + z) • (u + z))
… = √((u • u) + (u • z) + (z • u) + (z • z))
… = √(||u||² + 2 (u • z) + ||z||²)
We have
u = ⟨2, 12⟩ ⇒ ||u|| = √(2² + 12²) = 2√37
z = ⟨-7, 5⟩ ⇒ ||z|| = √((-7)² + 5²) = √74
u • z = ⟨2, 12⟩ • ⟨-7, 5⟩ = -14 + 60 = 46
and so
||w|| = √((2√37)² + 2•46 + (√74)²)
… = √(4•37 + 2•46 + 74)
… = √314 ≈ 17.720
Alternatively, without mentioning the dot product,
w = u + z = ⟨2, 12⟩ + ⟨-7, 5⟩ = ⟨-5, 17⟩
and so
||w|| = √((-5)² + 17²) = √314 ≈ 17.720
Using a graphical tool we obtain that the solution of this system
(intersection between the lines)
is given by the point
(x,y) = (2,4)
Answer:
a= Apple = 3
b= Banana =5
v= Lollypop=1
Step-by-step explanation:
36 is divided into 2 giving us 18
Let apple=a
Banana=b
Lollypop=c
In the first half
An apple + 3 bananas=18
a+3b=18 (1)
Second half is further divided into 2
That is,
18÷2=9
First half of the second half
3apples=9
3a=9 (2)
Second half of the second half
1 apple + 1 banana + 1 lollypop=9
a+b+c=9 (3)
a+3b=18 (1)
3a=9 (2)
a+b+c=9 (3)
From (2)
3a=9
Divide both sides by 3
a=9/3
a=3
Substitute a=3 into 1
a+3b=18
3+3b=18
3b=18-3
3b=15
Divide both sides by 3
b=15/3
=5
b=5
Substitute the value of a and b into (3)
a+b+c=9
3+5+c=9
8+c=9
c=9-8
c=1
Therefore,
a= Apple = 3
b= Banana =5
v= Lollypop=1
Answer:
<u><em>For x - y = 2</em></u>
You need to find x or y in one of the equations and then substitute that into the other.
So we have;
x-y=2
4x-3y=11
We will take the first equation and find x;
x-y=2
add y to both sides;
x-y+y=2+y
x=2+y
Now we take that answer and substitute it forx in the other equation;
4(2+y)-3y=11
8+4y-3y=11
8+y=11
y=3
Now we have what y equals, so we use it in the first equation to find x;
x-3=2
x=5
So we have;
x=5; y=3
Hope you understand!
=)
<u><em>And for 4x – 3y = 11</em></u>
Multiply the first equation by 2 and the second by 3 so that there are the same number of y's in each:
8x - 6y = 22 ...(3)
30x + 6y = -3 ...(4)
Now add (3) and (4) term by term:
38x + 0 = 19
or
38x = 19
or x = 1/2
Put this back into equation (1)
4*(1/2) - 3y = 11
or
2 - 3y = 11
Subtract 2 from both sides:
-3y = 9
Divide both sides by -3
y = -3
