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x = 6±sqrt( 31)

Step-by-step explanation:

x^2 -12x +5 =0

Subtract 5 from each side

x^2 -12x +5-5=0-5

x^2 -12x = -5

Take the coefficient of x

-12

Divide by 2

-12/2 =-6

Square it

(-6 )^2 = 36

Add this to each side

x^2 -12x +36= -5+36

(x-6)^2 = 31

Take the square root of each side

sqrt((x-6)^2) =±sqrt( 31)

x-6 =±sqrt( 31)

Add 6 to each side

x-6+6 =6±sqrt( 31)

x = 6±sqrt( 31)

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!

d. all of the above

step-by-step explanation: