Answer:
$5.00
Step-by-step explanation:
All we have to do is multiply 25 x 1/5 or 20%
25 x 1/5 = $5.00
to check, $5 x 5 = 25
The equation in standard form is 2x^2 + 7x - 15=0. Factoring it gives you (2x-3)(x+5)= 0. That's the first one. The second one requires you to now your formula for the axis of symmetry which is x = -b/2a with a and b coming from your quadratic. Your a is -1 and your b is -2, so your axis of symmetry is
x= -(-2)/2(-1) which is x = 2/-2 which is x = -1. That -1 is the x coordinate of the vertex. You could plug that back into the equation and solve it for y, which is the easier way, or you could complete the square on the quadratic...let's plug in x to find y. -(-1)^2 - 2(-1)-1 = 0. So the vertex is (-1, 0). That's the first choice given. For the last one, since it is a negative quadratic it will be a mountain instead of a cup, meaning it doesn't open upwards, it opens downwards. Those quadratics will ALWAYS have a max value as opposed to a min value which occurs with an upwards opening parabola. This one is also the first choice because of the way the equation is written. There is no side to side movement (the lack of parenthesis tells us that) so the x coordinate for the vertex is 0. The -1 tells us that it has moved down from the origin 1 unit; hence the y coordinate is -1. The vertex is a max at (0, -1)
Answer:
I need a picture to solve this.
Step-by-step explanation:
The number of minutes for which Keith was billed = 97
Step-by-step explanation:
Step 1:
It is given that Keith pays a fixed fee of 3$ a month and 11 cents per minute for the number of minutes used.
Total cost = Fixed cost + Per minute cost
If x represents the number of minutes consumed in a month then we can compute the total cost using the below equation:
Total cost = 3$ + 0.11 * x
Step 2:
The total cost is 13.67$
Substituting in the equation we get
13.67 = 3 + 0.11 * x
x = 10.67 / 0.11 = 97 minutes
Step 3:
Answer:
The number of minutes for which Keith was billed = 97
