CPhill

Fourth one

LM and NP  are equal distances from the center of the circle....so....they have equal length

Then.....they also span the same arcs

This implies that

(8x - 56)°  = (5x + 22)°

8x - 56  =  5x + 22          add 56  to both sides, subtract 5x from both sides

3x =  78      divide both sides by 3

x  =  26

So  LM spans an arc of   8(26) - 56  = 208 - 56  = 152°

And NP spans the same arc

So  LP  spans an arc  = 360 - LM - NP - MN =

(360 - 152  -152  - 39)°   =    17°

Third one

Since chords  DE  = GF....equal chords are the came distance from the center of the circle

This implies that  HJ  = JI   ....so....

3x + 20  =  15x  - 64         add 64 to both sides, subtract 3x from both sides

12x  = 84    divide both sides by 12

x  = 7

So JI   = 15x - 64  =  15(7) - 64  =  105 - 64  = 41

Second one.....same thing.....the chords LM and NP have the same length

So

41 - 2x  = 7x  +  5         add  2x to both sides.....subtract 5 from both sides

36  = 9x      divide both sides by  9

4   = x

So 

LM  = 41 - 2x   =   41 - 2(4)   =  41  - 8   =   33

I'll try a few

In the first one.....these chords have the same length....so....this implies that

(7x - 39)°  = 87°

7x - 39   = 87      add 39 to both sides

7x  =  126        divide both sides by 7

x  = 18

3(x^2 + 2x -3) - 4(4x^2 - 7x +5)  =

3x^2  + 6x - 9    -  16x^2 + 28x  -20  =

-13x^2 + 34x - 29

Ther's an algebraic solution which isn't difficult....but.....the easiest way to solve this is to divide 189  by 3  =

63 ....this is the middle odd integer

Add 2  to 63  = 65    ....this is the largest odd integer

Subtract 2 from 63   = 61......this is the smallest  odd integer

Answered here :

https://web2.0calc.com/questions/help_42954

 P(−1, 2) and Q(7, 8)  

The midpoint of  PQ   will be the center of the ciricle

So

( [ -1 + 7 ] /2 , [ 8 + 2 ] /2 )  = [ 6/2 , 10/2)  = (3 , 5)  = (h, k)

And the distance from this point to either P or Q   is  the radius, r 

And we can find r^2 as

(7 -3)^2  + ( 8 - 5)^2  = r^2

4^2 + 3^2  = r^2

16 + 9  = r^2

25 = r^2

So....the equation of the circle is

(x - h)^2  + (y - k)^2  = r^2

( x - 3)^2 + (y - 5)^2   = 25

We have 12 inches in one foot

So....to get the number ofv inches in  "m"  feet......multiply  by 12   ...so....

12m

OK.....!!!