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3 years ago

1/2s=4s-21 please show steps

Mathematics

1 answer:

omeli [17]3 years ago

4 0

Answer:

s = 6

Step-by-step explanation:

Goal is to isolate the variable (s)

1/2s = 4s - 21

Subtract 4s from both sides - this cancels out the 4s on the right side and moves it to the left side

1/2s - 4s = -21

To add or subtract fractions, they must have a common denominator

Convert 4s to a fraction over 2

1/2s - 8/2s = -21

Subtract the numerators and keep the denominators

-7/2s = -21

Remember the goal is to isolate the variable

In order to get rid of the -7/2, we multiply by its reciprocal (which is -2/7)

What we do to one side, we must do to the other (this means multiply by -2/7 on both sides

-7/2s × -2/7 = -21 × -2/7

s = -21 × -2/7

Negative × negative = positive

s = 42/7

Divide 42 by 7

s = 6

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A rectangle that is 2 inches by 3 inches has been scaled by a factor of 7.

loris [4]

Answer:

$New\ Lengths = (14,21)$

$New\ Scale\ Factor = \frac{1}{7}$

Step-by-step explanation:

Given

Rectangle:

Length = 2 in

Width = 3 in

Scale Factor = 7

Solving (a):

The side lengths of the new scale is calculated as follows;

New Lengths = Old Lengths * Scale Factor

$New\ Lengths = (2,3) * 7$

$New\ Lengths = (2 * 7,3* 7)$

$New\ Lengths = (14,21)$

Solving (b): To go back to the original length

Given that the initial scale factor is 7;

The new scale factor is the reciprocal of the old factor;

Hence;

$New\ Scale\ Factor = \frac{1}{7}$

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3 years ago

Angle Side Relationship 1/5 Will mark brainlist to whoever answers first

tresset_1 [31]

Answer:

m<A > m m<C

Step-by-step explanation:

In triangles, the measure of angles is proportional with the side length's they see,

The angle with the biggest the biggest measure sees the biggest side length

in triangle ABC the side lengths are given as

BC = 14, CA = 13 and AB = 5

from this, we can conclude:

m<A > m m<C

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2 years ago

What fraction of an hour is 42 minutes? Give your answer in its simplest form

lorasvet [3.4K]

$\frac{60}{42} = \frac{10}{7}$

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3 years ago

Is (3, 2) a solution of -8x – 2y < 6?

zzz [600]

Answer:

yes

Step-by-step explanation:

To determine if the point is a solution, substitute the coordinates into the left side of the inequality, evaluate and compare with right side.

- 8(3) - 2(2) = - 24 - 4 = - 28 < 6

Thus (3, 2) is a solution

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3 years ago

Read 2 more answers

What is the area of this composite figure? A. 135 cm2 B. 207 cm2 C. 249 cm2 D. 279 cm2

mariarad [96]

Answer:

249 cm^2

Step-by-step explanation:

This problem becomes easier if we subdivide the figure, find the areas of the resulting figures and then sum them up.

Draw a vertical line straight down from the edge marked "4 cm" towards the edge marked "18 cm." The resulting rectangle on the left is 15.5 cm long and (18 - 7.5) cm wide, or 15.5 by 10.5 cm. Its area is 162.75 cm^2.

Next, find the area of the rectangle on the right of the line we drew. Its width is 7.5 cm and its height (15.5 - 4) cm, resulting in an area of 86.25 cm^2.

Last, add together these two subareas: combine 86.25 cm^2 and 162.75 cm^2. The total area of the composite figure is then 249 cm^2 (answer).

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3 years ago