The function LaTeX: c\left(t\right)=1.75+0.85\left(t-1\ right)c ( t ) = 1.75 + 0.85 ( t − 1 ) represents the cost to call China as a function of the time, in minutes, t, on the phone. When will the cost first exceed $57?

Given:

The cost to call China as a function of the time, in minutes, t, on the phone is

To find:

The time when the cost first exceed $57.

Solution:

The cost first exceed $57 means cost is greater than $57.

Divide both sides by 0.85.

Therefore, after 66 minutes the cost to call china will exceed $57. It means first at t=67 the cost will exceed $57.

x ≥ 18 is your answer

step-by-step explanation:

let "a number" = x

(2/3)x + 17 ≥ 29

isolate the variable (x). do the opposite of pemdas (parenthesis, exponent (& root), multiplication, division, addition, subtraction).

first, subtract 17 from both sides.

(2/3)x + 17 (-17) ≥ 29 (-17)

(2/3)x ≥ 29 - 17

(2/3)x ≥ 12

next, multiply 3/2 to both sides to isolate the x

(3/2)(2/3)x ≥ 12(3/2)

x ≥ 12(3/2)

simplify. multiply, then divide

x ≥ (12 * 3)/2

x ≥ (36)/2

x ≥ 18

x ≥ 18 is your answer

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