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3 years ago

How do I solve this math question ?

Mathematics

2 answers:

exis [7]3 years ago

5 0

5x^2=75 divide both sides by 5

x^2=15 take the square root of both sides

x=√15

svlad2 [7]3 years ago

3 0

You do the square root of 75
and then with that number you divide it by 5
and that is your answer

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What place value is held by 3 in the number: 137,156

Rudik [331]

Tens of thousands. or the ten-thousands place.

7 0

3 years ago

A 4-foot tall child walks directly away from a 12-foot tall lamppost at 2 mph. How quickly is the length of her shadow increasin

xz_007 [3.2K]

Answer:

The length of the shadow is increasing with the rate of 1.5 feet per sec

Step-by-step explanation:

Let AB and CD represents the height of the lamppost and child respectively ( shown below )

Also, let E be a point represents the position of child.

In triangles ABE and CDE,

$\angle ABE\cong \angle CDE$ ( right angles )

$\angle AEB\cong \angle CED$ ( common angles )

By AA similarity postulate,

$\triangle ABE\sim \triangle CDE$

∵ Corresponding sides of similar triangles are in same proportion,

$\implies \frac{AB}{CD}=\frac{BE}{DE}$

We have, AB = 12 ft, CD = 4 ft, BE = BD + DE = 6 + DE,

$\implies \frac{12}{4}=\frac{6+DE}{DE}$

$12DE = 24 + 4DE$

$8DE = 24$

$DE=3$

Now, the speed of walking = 2 mph = $\frac{2\times 5280}{3600}\approx 2.933\text{ ft per sec}$

Note: 1 mile = 5280 ft, 1 hour = 3600 sec

Thus, the time taken by child to reach at E

$= \frac{\text{Walked distance}}{\text{Walking speed}}$

$=\frac{6}{2.933}$

= 2.045 hours

Hence, the change rate in the length of shadow

$= \frac{\text{Length of shadow}}{\text{Time taken}}$

$=\frac{3}{2.045}$

= 1.5 ft per sec.

3 0

2 years ago

Mr. Ortiz has 3/4 pound of oatmeal.

ki77a [65]

Answer:

$\frac{1}{4}\ pound$

Step-by-step explanation:

$We\ are\ given:\\Amount\ of\ oatmeal\ Mr.Ortiz\ has=\frac{3}{4}\ pounds \\Amount\ of\ Oatmeal\ he\ uses\ to\ bake\ muffins=\frac{2}{3}\ of\ the\ amount\ he\ had\\Now,\\Lets\ first\ find\ the\ amount\ of\ oatmeal\ he\ used=\frac{3}{4}*\frac{2}{3}=\frac{1}{2}\ pounds\\Hence,\\The\ amount\ of\ oatmeal\ remains=Total\ amount\ of\ oatmeal-Amount\\ he\ used\ to\ make\ muffins\\Hence,\\The\ amount\ of\ oatmeal\ left\ with\ Mr.\ Ortiz=\frac{3}{4} - \frac{1}{2} =\frac{1}{4}\ pound$