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2 years ago

-2x-y=-9 5x-2y=18 substitution

2 answers:

6 0

$-2x-y=-9 \\
5x-2y=18 \\ \\
\hbox{solve the first equation for y:} \\
-2x-y=-9 \ \ \ |+2x \\
-y=-9+2x \ \ \ |\times (-1) \\
y=9-2x \\ \\
\hbox{substitute 9-2x for y in the second equation:} \\
5x-2(9-2x)=18 \\
5x-18+4x=18 \\
9x-18=18 \ \ \ |\div 9 \\
x-2=2 \ \ \ |+2 \\
x=4 \\ \\
y=9-2x=9-2 \times 4=9-8=1 \\ \\
\boxed{(x,y)=(4,1)}$

Inessa05 [86]2 years ago

4 0

-2x-y = -9 5x-2y=18 -solve for y in terms of x -y= 2x-9 y=-2x+9 substitute 5x-2 ( -2x+9)=18 5x+4x -18=18 9x-18=18 9x= 36 x=4 substitute for x -2 (4) -y= -9 -8 -y = -9 -y = -1 y= 1 ANSWER x= 4 y=1 hope this helps

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Answer:

A= 66.6667

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Step-by-step explanation:

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Initial value of B = $80

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A moves up 50% = 20+10

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B double it values = $80*2

B double it values = $160

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A20+B80= 28000... equation 1

A30+B160= 54000.... equation 2

Multiplying equation 1 * 2

Multiplying equation 2 * 1

A40 +B160 = 56000

A30+B160= 54000

A30 = 2000

A= 2000/30

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Substituting A

200/3 (20) +B80= 28000

B80= 28000-4000/3

B80= 80000/3

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2 years ago

What is the area of the shape below

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Answer:

The area of the shape is $A=886 \:cm^2$ .

Step-by-step explanation:

The shape in the graph is a composite figure is made up of several simple geometric figures such as triangles, and rectangles.

Area is the space inside of a two-dimensional shape. We can also think of area as the amount of space a shape covers.

To calculate the area of a composite shape you must divide the shape into rectangles, triangles or other shapes you can find the area of and then add the areas back together.

First separate the composite shape into three simpler shapes, in this case two rectangles and a triangle. Then find the area of each figure.

To find the area of a rectangle, we multiply the length of the rectangle by the width of the rectangle.

The area of the first rectangle is $A=34\cdot 16=544\:cm^2$

The area of the second rectangle is $A=11\cdot19=209\: cm^2$

The area of a triangle is given by the formula $A=\frac{1}{2} bh$ where b is the base and h is the height of the triangle.

The area of the triangle is $A=\frac{1}{2} \cdot 14\cdot19=133\:cm^2$

Finally, add the areas of the simpler figures together to find the total area of the composite figure.

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