Answer:
Anita's monthly bill will be $164.25.
Step-by-step explanation:
Since Anita has a cellphone contract that costs her R100 per month plus 85 cents per peak time SMS, and 25 cents per off-peak time SMS, if she sends 45 SMSs during peak time and 105 SMSs during off-peak time In a month To determine what will her monthly bill come to, the following calculation must be performed:
100 + (0.85 x 45) + (0.25 x 105) = X
100 + 38.25 + 26.25 = X
138.25 + 26.25 = X
164.25 = X
Therefore, her monthly bill will be $ 164.25.
The answer is <span>252.5 ft
</span><span>y = –0.004x</span>²<span> + x + 2.5
Let's take y = 0 and we'll get the quadratic equation:
</span>–0.004x² + x + 2.5 = 0
The general formula for quadratic equation is:
ax² + bx + c = 0
a = -0.004
b = 1
c = 2.5
![x_{1,2} = \frac{-b+/- \sqrt{ b^{2}-4ac} }{2a} =\frac{-1+/- \sqrt{ 1^{2}-4*(-0.004)*2.5} }{2*(-0.004)} = \frac{-1+/- \sqrt{1+0.04} }{-0.008} = \\ =\frac{-1+/- \sqrt{1.04} }{-0.008} = \frac{-1+/-1.02}{-0.008}](https://tex.z-dn.net/?f=x_%7B1%2C2%7D%20%3D%20%5Cfrac%7B-b%2B%2F-%20%5Csqrt%7B%20b%5E%7B2%7D-4ac%7D%20%7D%7B2a%7D%20%3D%5Cfrac%7B-1%2B%2F-%20%5Csqrt%7B%201%5E%7B2%7D-4%2A%28-0.004%29%2A2.5%7D%20%7D%7B2%2A%28-0.004%29%7D%20%3D%20%5Cfrac%7B-1%2B%2F-%20%5Csqrt%7B1%2B0.04%7D%20%7D%7B-0.008%7D%20%3D%20%5C%5C%20%0A%3D%5Cfrac%7B-1%2B%2F-%20%5Csqrt%7B1.04%7D%20%7D%7B-0.008%7D%20%3D%20%5Cfrac%7B-1%2B%2F-1.02%7D%7B-0.008%7D%20)
![x_1=\frac{-1+1.02}{-0.008} = \frac{0.02}{-0.008} = -2.5 \\ x_2=\frac{-1-1.02}{-0.008} = \frac{2.02}{-0.008} = 252.5](https://tex.z-dn.net/?f=x_1%3D%5Cfrac%7B-1%2B1.02%7D%7B-0.008%7D%20%3D%20%5Cfrac%7B0.02%7D%7B-0.008%7D%20%3D%20-2.5%20%5C%5C%20%0Ax_2%3D%5Cfrac%7B-1-1.02%7D%7B-0.008%7D%20%3D%20%5Cfrac%7B2.02%7D%7B-0.008%7D%20%3D%20252.5)
Since distance cannot be negative (x1), the correct answer is x2 = 252.5 ft
The direct variation between x and y may be written as,
y = kx
where k is the constant of variation. From the first set of values of the variables,
12 = k(8)
the value of k is 1.5. Substituting the next set to the same equation,
y = 1.5(14)
The value of y is 21.
Answer: 3
Step-by-step explanation:
4x+23=7x+14
4x-7x=14-23
-3x=9
x=9/3
x=3
Answer:
133.33g
Step-by-step explanation:
Let the:
Mass of 1.2g/cm³ of liquid = x
Mass of 1.8g/cm³ of liquid = y
From our Question above, our system of equations is given as:
x + y = 400........ Equation 1
x = 400 - y
1.2 × x + 1.8 × y = 1.6 × 400
1.2x + 1.8y = 640..... Equation 2
We substitute, 400 - y for x in Equation 2
1.2(400 - y) + 1.8y = 640
480 - 1.2y + 1.8y = 640
- 1.2y + 1.8y = 640 - 480
0.6y = 160
y = 160/0.6y
y = 266.67 g
Solving for x
x = 400 - y
x = 400 - 266.67g
x = 133.33g
Therefore, the mass of the liquid of density 1.2g/cm³ is 133.33g