CPhill

Here's (1)

 [154 + 190 + 143 + 180 +125  + x ]  / 6 =   160      simplify

[792 + x ] / 6    = 160      multiply both sides by 6

792 + x   = 960      subtract  792 from both sides

x = 168  =  Answer C

This explains it pretty well :   http://www.purplemath.com/modules/quadform.htm

$20.00 -$6.47 =  $13.53

-1/5*-10+(-4-7)-152  work in the parentheses, first

-1/5 * (-10) + (-11) - 152     perform the multiplication, next

2 -11 - 152         now, simplify

-161

51.3 ft/s x 7.1 s   =  364.23 ft

8.67x10^-5   =

.0000867

(X-3)(2X+4)  = 

2x^2 - 6x + 4x - 12   = 

2x^2 - 2x - 12

We either have

(2a)³  = (2[4])³  = 8³  = 512

Or

2a³  = 2(4)³   = 2(64)  =  128 

0=9/5c+32     subtract 32 from both sides

-32 = (9/5)C    multiply both sides by 5/9

(5/9)(-32)  = C  = about -17.77

h= h*1.11 + 0.2785      subtract 1.11h from both sides

h - 1.11h = 0.2785       factor out the h on the left side

h( 1 - 1.11)  = 0,2785    simplify

h (-.11)  = 0.2785     divide both sides by -.11

h = .2785 / -.11 

h = about  -2.53