Answer:
f(3) ≈ 17.310
Step-by-step explanation:
e = 2.71828
Step 1: Define
f(x) = e2x - 1 + 2
x = 3
Step 2: Substitute and evaluate
f(3) = e2(3) - 1 + 2
f(3) = 6e + 1
f(3) = 16.3097 + 1
f(3) = 17.3097
f(3) ≈ 17.310
We know that
• Lashonda purchased a prepaid phone card for $20.
,
• Long-distance calls cost 8 cents a minute.
,
• The remaining credit on her card is $17.12.
This problem can be expressed as
Where <em>x</em> is the number of minutes.
We solve the equation for <em>x</em>
Then, we divide by -0.08 the equation
<h2>Therefore, Lashonda's call last 36 minutes.</h2>
Let the shortest side be = a, then side b = 2·a and side c = (b + 24)
We are given that a + b + c = 84
Substituting for b and c
a + 2·a + (a + 24) = 84
4·a + 24 = 84
4·a = 84 - 24 = 60
a = 60/4 = 15 feet
b = 2·15 = 30 feet
c = 15 + 24 = 39 feet
sorry if i am wrong
Try this:
1) note that weight of pure antifreeze before mixing and after mixing is the same. So, if 'x' is weight of pure antifreeze in 50% solution, it is possible to make up equation before mixing: 0.5x+0.2*90.
2) there are 0.2*90=18 gal. of pure antifreeze in the 20% solution. If 'x' gal. is the weight of pure antifreeze in 50% sol. and 18 gal. is the weight of pure antifreeze in 20% sol., it is possible to make up an equation after mixing: 0.4(x+18).
3) using the both parts: 0.5x+0.2*90=0.4(x+18) ⇒ x=54 gal. of <u>pure</u> weight.
4) to find 50% solution of 54 gal. pure weight just 54:0.5=108 gal.
Answer: 108 gal.
