Answer:
x=13
Step-by-step explanation:
119-2=117
117÷9=13
9×13+2=119
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)
I believe that it is 2x^2+1x-2
Answer:
Step-by-step explanation:
Neutron: has mass and no charge
Protons: has mass and a positive charge
Teachers often all this problem a donut problem because it’s like the donut hole getting cut out of the middle. The way that you solve this is to find the area of the whole yard and subtract the area of the fountain. Since they are rectangles we’re going to use A = LW
Area of yard - Area of fountain
A = (8x)(9x) - (2x)(5x)
A = 72 x^2. - 10 x^2
A 62 x^2
