it is 40.5 because area equals base times height.
We know that the points at which the parabola intersects the x axis are
(-5,0) and (1,0)
So the extent between these two points would be the base of the triangle
lets find the length of the base using the distance formula
![\sqrt{[(-5-1)^{2}+(0-0)^{2} ]}](https://tex.z-dn.net/?f=%20%5Csqrt%7B%5B%28-5-1%29%5E%7B2%7D%2B%280-0%29%5E%7B2%7D%20%5D%7D%20%20)
the base b=6
We will get the height of the triangle when we put x=0 in the equation
y=a(0+5)(0-1)
y=-5a
so height = -5a (we take +5a since it is the height)
We know that the area of the triangle =
× 6 × (5a) = 12
15a=12
a= 
Answer:
Step-by-step explanation:
let x and y be length and width of rectangle.
Perimeter=2(x+y)
area=xy
2(x+y)=1/2 xy
4(x+y)=xy
4x+4y=xy
x y-4y=4 x
y(x-4)=4 x

Answer:
x = 0
, y = 4
Step-by-step explanation:
Solve the following system:
{y = 4 - 3 x | (equation 1)
x + 2 y = 8 | (equation 2)
Express the system in standard form:
{3 x + y = 4 | (equation 1)
x + 2 y = 8 | (equation 2)
Subtract 1/3 × (equation 1) from equation 2:
{3 x + y = 4 | (equation 1)
0 x+(5 y)/3 = 20/3 | (equation 2)
Multiply equation 2 by 3/5:
{3 x + y = 4 | (equation 1)
0 x+y = 4 | (equation 2)
Subtract equation 2 from equation 1:
{3 x+0 y = 0 | (equation 1)
0 x+y = 4 | (equation 2)
Divide equation 1 by 3:
{x+0 y = 0 | (equation 1)
0 x+y = 4 | (equation 2)
Collect results:
Answer: {x = 0
, y = 4