ElectricPavlov

y=-3/5(x-0)^2+3 =

y = -3/5 x^2 + 3             Is this the standard form? ( I don't know)

y + 3/5 x^2 -3 = 0           Is the the Standard form you are looking for?

5y + 3x^2 - 15 = 0           Another form.......they are all equal .....

This is not a right triangle ...and no angles are given . Only the side lengths are given.   You COULD use cos law  to calculate the angles and start from there but it would be easier to use Heron's Formula to calculate the area...are you familiar with it ?

This is a Math Forum....people go here to get help with math problems.  It really isn't set up as  a place for chatting back and forth, which clutters the site .  You should go look for a different forum for chatting with people.   G 'Luck !   

2x = 56 ^o          or      E + 56 = 2x  + E     ( both sides equal a straight line )

What part do you not understand?

Shaded area is everything above the line but not including the line

line equation is  y = 1/2x - 1/2

answer   y > 1/2x - 1/2     <======== you have this listed as incorrect answer....but it IS correct !   You just need to complet the work to get it in the correct form....don't be a lazy person just looking for the answer !

y > 1/2x - 1/2

0 > 1/2x - 1/2 - y     multiply by 2

0 > x - 1 - 2y

  or        x - 2y -1 < 0

Here is a desmos graph:

https://www.desmos.com/calculator/acwb5p136t

5x^2 - 20x + 1357 - 80x + 415 = 0

5x² -100x + 1772 = 0        Bowl shaped parabola ...  minumum value of the function will occur at the x value = - b/2a =  - -100/10 = 10

                                               use this value of 'x' in the equation to compute the minimum value of the fxn.

From that picture it appears you can wait a LOT longer with no ill-effects !    LOL

I'm not really 'fat'      my BMI is pretty low.....I just have big hands !    a.k.a.  Fat fingers ( in comparison to the keyboard spacing)      Haha

50% = 1/2

so we are counting    1/2 + 1/20  + 1/10    =  13/20 from the total

   ( 1 - 13/20 ) x   =  70 students

           7 /20  x = 70

       x = TOTAL students = 70 * 20 /7   = 200 students

1/20 are 10 y/o     1/20 * 200 = 10 students are 10 y/o