23 - (-14) = 23 + 14 = <em><u>37</u></em>
128 - (-105) = 128 + 105 = <em><u>233</u></em>
Total Cost = 55+0.35x
X represents the amount of minutes you spend talking on the phone.
point 1 = ( -1 , 5 ) point 2 = ( 5 , -5 )
equation of a line: y = mx + b
Find Slope (m):
( 5 - (-5)) / (-1 - 5))
= 10 / -6
= -3 / 2
slope = -3/2
Find y-intercept (b):
y = mx + b
y = -3/2 * x + b
5 = -3/2 * -1 + b <-------------- use the x and y coordinate of one of the . points. I used point 1 ( -1 , 5 )
b = 7/2 or 3.5
Assemble:
y = -3/2 * x + 3.5
<span>9.095 divided by 0.17 is 53.50
</span>
Http://www2.ccsd.ws/sbfaculty/team8e/jecole/Math/Two%20step%20Equations.htm this link explains it all