So we do 21-9=12 so then we now know that the rectangle is 12 so then we do 12*8 units which is= 96 . Now the triangles. so the first one we know that its 8*3 and times it by 1/2 because two triangles is equal to a rectangle so the first triangle is 12 and now the second. its 9-3= 6 then its 6*8*1/2 which is equal to 24 so now the final answer is

96+12+24 which is equal to 132 so i'm guessing it 132 square units

5 0

2 years ago

Andrews math teacher entered the seventh- grade students in a math competition. There was an enrollment fee of $30 and also an $

Anon25 [30]

Answer:

Step-by-step explanation:

You would start by subtracting $30 from $151 which is $121.

Then you would divide this by 11 which 121÷11=11

So 11 test were bought.

7 0

2 years ago

A farmer has 1,200 feet of fencing and wants to fence off a rectangular field that borders a straight river. He needs no fence a

iVinArrow [24]

Yay, derivitives
I'mma ignore that x is the shorter side because I don't know which one has to be shorter yet

we need to find the max area
but with 3 sides

area=LW
let's say the sides are z and y
zy=area

and the relatiionship between them is
hmm,
z+2y=1200
because one side has no fencing
so
z+2y=1200
solve for z
z=1200-2y
sub for z in other

(1200-2y)(y)=area
expand
1200y-2y²=area
take derivitive
1200-4y=dy/dx area
max is where dy/dx goes from positive to negative
solve for where dy/dx=0
1200-4y=0
1200=4y
300=y

at y<300, dy/dx<0
at y>300, dy/dx>0
so at y=300, that is the max

then
z=1200-2y
z=1200-2(300)
z=1200-600
z=600

so then
z=600
y=300
300<600

so the shorter side would be y

so then we see our choices and noticed that
erm
I think it is f(x)=1200x-2x²
takind the derivitive yeilds none of the others

so ya, you are right

6 0

2 years ago

Read 2 more answers

Mary wants to hang a mirror in her room. The mirror and frame must have an area of 7 square feet. The mirror is 2 feet wide and

Umnica [9.8K]

Answer:

The quadratic equation used to determine the thickness of frame is $\left(3+2x\right)\times \left(2+2x\right)=7$