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2 years ago

Solve the equation using the zero-product property. (2x − 8)(7x + 5) = 0 x = –2 or x = 7 x = 4 or x = x = 4 or x = x = –4 or x =

1 answer:

5 0

$(2x-8)(7x+5)=0\iff2x-8=0\ \vee\ 7x+5=0\\\\2x-8=0\qquad\text{add 8 to both sides}\\2x=8\qquad\text{divide both sides by 2}\\\boxed{x=4}\\\\7x+5=0\qquad\text{subtract 5 from both sides}\\7x=-5\qquad\text{divide both sides by 7}\\\boxed{x=-\dfrac{5}{7}}$

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Please help 100 points and brainlest for all the answers

masha68 [24]

Answer:

See explanation

Step-by-step explanation:

Q1. The graph of given data is attached.

The relationship is directly proportional as the line connecting all points is straight line passing through the origin.

For every 1 unit change in x, the change of y is 16.

Therefore, the equation that represents this line is

$y=16x$

If $x=10,$ then $y=16\cdot 10=160$ square feet.

Q2. Yes, the relationship shows the direct proportionality as the line connecting all points is straight line passing through the origin (see second attached graph).

For every 1 unit change in x, the change of y is 0.45.

Therefore, the equation of the line is

$y=0.45x$

Q3. Yes, the relationship shows the direct proportionality as the line connecting all points is straight line passing through the origin.

Find the constant of proportionality:

If x = 2, y = 25, then

when x = 1, y = 12.5

so k = 12.5

and the equation of the line is

$y=12.5x$

When $x=14,$ then $y=12.5\cdot 14=175$

Hence, the cost of 14 tickets is $175

Q4. This table does not show the direct variation because

if x = 500 and y = 40, then

for x = 100, y is $40\div 5=8$

and for x = 700, y must be $7\cdot 8=56$ not 50.

Hence, this relationship does not show the direct proportionality between x and y.

Q5. This elationship shows the direct proportionality as the line connecting all points is straight line passing through the origin.

The constant of proportionality is $k=1.75$

The equation of proportionality is $y=1.75x$

When $y=28,$ then

$28=1.75x\\ \\x=\dfrac{28}{1.75}\\ \\x=16$

This means for $28 you could buy 16 ice cream scoops.

Q6. The line passes through the point (2,61), so the constant of proportionality is

$k=\dfrac{61}{2}=30.5$

The equation of proportional relationship is

$y=30.5x$

When $y=274.50,$ then

$274.50=30.5x\\ \\x=\dfrac{274.5}{30.5}\\ \\x=9$

This means you could buy 9 tickets for $274.50

Q7. The equation which represent proportional relationship should have the equation of the form

$y=kx$

Circle all equations in this form:

$y=5x\\ \\p=0.5m\\ \\y=\dfrac{1}{2}x\\ \\M=3n\\ \\y=2x$

Q8. A relationship between two variables in which one is a constant multiple of the other. In particular, when one variable changes the other changes in proportion to the first. If y is directly proportional to x, the equation is of the form y = kx (where k is a constant).

This means that the graph of direct variation is always a straight line passing through the origin (because x = 0 and y = 0 satisfy the equation for all k).

Not all lines represent the proportional relationship. Only those, which pass through the origin.

4 0

2 years ago

Read 2 more answers

Use the information in the diagram to determine the height of the tree to the nearest foot.

algol13

Answer:

The correct option is A. The height of tree is 60 ft.

Step-by-step explanation:

From the given figure it is noticed that the building is creating a right angle triangle from a point and the tree divides the hypotenuse and base in two equal part.

According to midpoint theorem of triangle: In a triangle, if a line segment connecting the midpoints of two sides, then the line is parallel to third side. The length of line segment is half of the length of third side.

Using midpoint theorem of triangle, we can say that the length of tree is half of the building.

$Tree=\frac{1}{2}\times Building$