3(x-7)+8=-20
Multiply the bracket by 3
(3)(x)(3(-7)+8= -20
3x-21+8= -20
3x-13= -20
Move -13 to the other side. Sign changes from -13 to +13.
3x-13+13= -20+13
3x= -7
Divide by 3
3x/3= -7/3
x= -7/3 or in mixed number : -2 1/3
Answer : x= -7/3 or in mixed number : -2 1/3
Let C and d be the circumference and diameter of a circle, respectively. Then
C = πd
so that
π = C/d = C/12
I think it is 640.. What they mean is every inch equals 4 feet so you would multiply 8*4 and 5*4 then you get 32 and 20.. im sure you know area but just incase its base times height so 32*20=640
Answer:
8 miles
Step-by-step explanation:
We start by calculating the distance between the two points
To calculate this, we use the distance formula
Let the distance be D
We have the formula as;
D = √(x2-x1)^2 + (y2-y1)^2
D = √(-2+2)^2 + (-5-3)^2
D = √(64)
D = 8 units
Since 1 unit is 1 mile,
then 8 units will be 8 * 1 = 8 miles
For polar form you need to find the modulus (length of the vector) and the argument (angle of the vector) and present in form rcis(Arg) or re^Argi
start with the modulus r=sqrt(a^2 +b^2)
=sqrt(-2^2 +2^2)
= sqrt(4+4)
=sqrt(8)
=2sqrt(2)
next the argument, firstly arg=tan(b/a)
= tan(2/2)
=tan(1)
=pi/4 . (exact values table)
Now consider the quadrant the complex number is in, as it is (-2,2) it is in the second quadrant and as such your Arg value is:
Arg=pi-arg
= pi-pi/4
= 3pi/4
add it all together and your complex number in polar form is:
2sqrt2cis(3pi/4)
note: cis is short hand for cos(x)+isin(x), it is possible your tutor would rather you use the complex exponential form which is simply re^Argi and your answer would look like:
2sqrt2e^(3pi/4)i
Also notice the difference between arg and Arg as this often slips students up and always present Arg in prinicple argument form ie -pi<Arg<pi
Hopefully this has been clear enough and good luck
