10x^5+25x+75 that will be your answer
Ok... so this question can be solved by using simultaneous equations.
Use the general from of a parabola

you know the value of c, the y-intercept... y = -4
which means the equation is

now use the other 2 points to get 2 equations in 2 unknowns
(-2, -20) just substitute

this becomes

now the other equation using (4, -20)
The simplified form is
Solve for x: x^2+4x-5=16x
first take 16x from both sides of the equation
x²-12x-5=0
now we have a quadratic. we can solve it by using the quadratic formula
x=-b plus or minus the square root of b²-4ac all divided by 2a
where a=1, b=-12 and c=-5
plug these numbers into the formula
x=12 plus or minus the square root of 144-4x1x-5 all divided by 2
<span>x=12 plus or minus the square root of 164 all divided by 2
or in decimal form </span>x = {12.403124237, -0.403124237}
Answer: -30
Step-by-step explanation: