Answer:
The answer is "0.5".
Step-by-step explanation:
Given:
3) x² - 121 = 0
x² = 121
x' = +√121
x' = 11
_______________
x'' = - √121
x'' = -11
Solution ⇒ S{-11 ; 11 } or (x-11)(x+11)
4) 4x² + 144 = 0
4x² = -144
x² = -144 / 4
x² = -36
x = √-36
No solution ⇒ S = ∅
5) z²+10z+21 = 0
Δ = 10² - 4(1)(21)
Δ = 100 - 84
Δ = 16
x' = (-10+4) / 2 = -6/2 = -3
x'' = (-10-4) / 2 = -14/2 = -7
Solution ⇒ S{ -7 ; -3} or (x+3)(x+7)
Set up an equation to solve.
$8.50x (since it is the rate of change) + $12 (flat fee) = total money earned (or y). In this case, we have the total, amount, and are looking for x. Plug $139.50 into the equation.
$8.50x + $12 = $139.50
Now, solve for x.
$8.50x + $12-12 = $139.50-12 > <em>$8.50x = $127.5</em>
$8.50/8.50x = $127.5/8.50 > <em>x = 15</em>
So, the correct answer is <u>D. Olivia babysat for 15 hours.</u>
118 text messages.
59.50-30=29.5
29.5 divided by 0.25=118.
I hope this is right! :) Sorry if it isn’t!
