WILL MARK BRAINLIEST IF YOU SOLVE THIS PLEASE

Help me Please!! Ive got a deadline!! Thanks! (:

saul85 [17]

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)

3 0

3 years ago

In planning her retirement, Liza deposits some money at 2.5% interest, with twice as much deposited at 4.5%. Find the amount dep

Harlamova29_29 [7]

Let us assume $x is deposit at 2.5% interest.

At the rate 4.5% deposited amount is twice of the amount deposited at 2.5%.

Therefore, at the rate 4.5% deposited amount = $2x.

Total interest earned by both different deposited amount at the rate 2.5% and at the rate 4.5% = $1150.

We can setup an eqation now,

Interest earned on $x at 2.5% + interest earned on $2 at 4.5% = $1150.

2.5% of x + 4.5% of 2x = 1150

Percentage could be written in decimals by dividing by 100.

Therefore, 2.5% = 2.5 /100= 0.025 and 4.5% = 4.5/100 = 0.045.

We could rewrite above equation as,

0.025*x + 0.045 * 2x = 1150

0.025x + 0.09x =1150

Adding 0.025x + 0.09x, we get 0.115x.

So, 0.115x=1150.

Dividing both sides by 0.115.

0.115x/0.115=1150/0.115.

x= $1000.

2x= 2* 1000= $2000

Therefore,

$1000 deposited at 2.5% and $2000 deposited at 4.5%.

7 0

3 years ago

What i -5 5/12 written a a decimal

Helen [10]

-5 5/12 =-5.416
(: :)
(:

7 0

2 years ago

Annie walks 15 feet away from her house and places a mirror on the ground. She backs 4 feet away from the mirror so that she can

artcher [175]

Answer:

The house is 18.75 feet tall

Step-by-step explanation:

The triangles are similar by the AA postulate.

We are given the length of the bottom sides of the triangles, 4 and 15 respectively.

Thus, the ratio is 4:15

We are also given the height of Annie's eyes, which is 5 feet. The height of the side that corresponds to the house is 5, so we can set up a proportion.

$\frac{4}{15} = \frac{5}{x} \\4x = (5*15) = 75\\x = \frac{74}{4} \\x = 18.75$

Thus, the house is 18.75 feet tall.

5 0

3 years ago

2/5 gallon of paint can cover 3 walls. How many walls can 1 gallon of paint cover?

AnnyKZ [126]

Answer:

one gallon of paints can cover about 2 walls.

3 0

2 years ago