Answer:
B. y = -3/4x + 5/2
Step-by-step explanation:
Take two points from the graph, let's use (-2, 4) and (2, 1):
Find slope:
m = (y₂ - y₁) / (x₂ - x₁)
= (1 - 4) / (2 - (-2))
= -3/4
Find y-intercept using slope above and anyone point:
y = mx + b
(1) = -3/4(2) + b
1 = -3/2 + b
b = 1 + 3/2
b = 5/2
Equation of line using m and b above:
y = mx + b
y = -3/4x + 5/2
<h3>Answers:</h3>
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Explanation:
x = number of seconds that elapse
y = altitude (aka height) of the plane
The equation for plane A is
y = 20.25x+2652
because it starts off at 2652 ft in the air, and then adds on 20.25 feet per second which is what the 20.25x describes
The equation for plane B is
y = 75.5x
The y intercept is zero because plane B starts on the ground, aka height 0.
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The system of equations is
If we want to know when they'll reach the same height (y), then we can set the two right hand sides equal to each other and solve for x.
75.5x = 20.25x+2652
75.5x-20.25x = 2652
55.25x = 2652
x = (2652)/(55.25)
x = 48
The two planes reach the same altitude at exactly <u>48 seconds</u>
That altitude is <u>3624 feet</u> because
- y = 20.25*x + 2652 = 20.25*48+2652 = 3624
- y = 75.5*x = 75.5*48 = 3624
Notice I plugged x = 48 into each equation and I got the same y value of y = 3624. This helps confirm the answers.
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)
Logarithm properties:
According to this, we can get:
Answer:
13
Step-by-step explanation:
