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2 years ago

Evaluate the expression for x = 2. -9x2 + 11x − 7 =

Mathematics

2 answers:

8_murik_8 [283]2 years ago

6 0

Follow order of operations.

(Replace x with 2)

-9x2 + 11x − 7 =

-9(2)*2+11(2)-7

-9*2=-18*2= -36

11*2=22-7= 15

-36+15 = -21

Answer: -21 :)

- Liebesleid

harina [27]2 years ago

4 0

All you have to do is replace every x with 2 and then solve:

Make to sure to follow the Order of Operations!!

-9x(2) + 11x - 7 =

(-9 × 2 × 2) + (11 × 2) - 7 =

-36 + 22 - 7 =

-14 - 7 =

-21

The answer is -21.

Hope that helps!

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The Garden Task

Igoryamba

If the perimeter of the garden is (14x - 32) ft and has a side length of (x + 2) ft:

the perimeter = 24 ft
the area = 36 sq. ft
if the perimeter of the garden is doubled, the perimeter of the new garden = 48 ft
if the area of the garden is doubled, the area of the new garden = 72 sq. ft

Recall:

A square has equal side lengths
Perimeter of a square = 4(side length)
Area of a square = $(side $ length)^2$

Given:

Perimeter of square (P) = $(14x - 32) $ ft$

Side length (s) = $(x + 2) $ ft$

First, let's find the value of x by creating an equation using the perimeter formula:

Perimeter of a square = 4(side length)

Plug in the values

$(14x - 32) = 4(x + 2)$

Solve for x

$14x - 32 = 4x + 8\\\\14x - 4x = 32 + 8\\\\10x = 40\\\\x = 4$

Find how much fencing would be needed (Perimeter of the fence):

Perimeter of the fence = $(14x - 32) $ ft$

Plug in the value of x

Perimeter of the fence = $14(4) - 32 = 24 $ ft$

Find the area of the garden:

Area of the garden = $(side $ length)^2$

Area = $(x + 2)^2$

Plug in the value of x

Area = $(4 + 2)^2 = 6^2 = 36 $ ft^2$

Find the perimeter if the garden size is doubled:

Perimeter of the new garden = 2 x 24 = 48 ft

Find the area if the garden size is doubled:

Perimeter of the new garden = 2 x 36 = 72 sq. ft

In summary, if the perimeter of the garden is (14x - 32) ft and has a side length of (x + 2) ft:

the perimeter = 24 ft
the area = 36 sq. ft
if the perimeter of the garden is doubled, the perimeter of the new garden = 48 ft
if the area of the garden is doubled, the area of the new garden = 72 sq. ft