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3 years ago

What is the solution to x-y=5 and x+y=3?

Mathematics

1 answer:

Romashka [77]3 years ago

7 0

Answer:x=4 , y=-1

Step-by-step explanation:

X-y=5

X+y=3

If 1 and 2 are added then y will be eliminated

(1)+(2) gives : 2x=8 then x=4

Now substitute this value of x into either of the 2 equations and solve for y.

Let x=4 in (1) =4-y=5 = y=-2

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Find 2(−5)(−6)−(−12)

Alisiya [41]

Answer:

Step-by-step explanation:

2*-5=-10

-10*-6=60

60-(-12)=60+12=72

3 0

3 years ago

Work out the value of 10 fourths

lora16 [44]

Answer:

10/4 equals 2 1/2 when simplified.

Step-by-step explanation:

10/4 = 2 2/4 or 2 1/2 when simplified.

This is because, 4 x 2 = 8, and 8 + 2 (or 1/2 of 4) = 10.

Hope this helps! :D

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3 years ago

Is 314.15927 irrational or rational

Marizza181 [45]

Answer:

3.14159... is irrational. Is that what you mean? What you put right now is rational

Step-by-step explanation:

Irrational = infinite

Rational = Not infinite

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3 years ago

The length of a rectangle is increasing at a rate of 9 cm/s and its width is increasing at a rate of 4 cm/s. When the length is

Setler [38]

Answer:

The area of the rectangle is increasing at a rate of 168 square centimeters per second.

Step-by-step explanation:

Geometrically speaking, the area of a rectangle ( $A$ ), in square centimeters, is described by following expression:

$A = w\cdot l$ (1)

Where:

$w$ - Width, in centimeters.

$h$ - Height, in centimeters.

By Differential Calculus, we find an expression for the rate of change of the area of the rectangle ( $\dot A$ ), in square centimeters per second:

$\dot A = \dot w\cdot l + w\cdot \dot l$ (2)

Where:

$\dot w$ - Rate of change of the width of the rectangle, in centimeters per second.

$\dot l$ - Rate of change of the length of the rectangle, in centimeters per second.

If we know that $w = 12\,cm$ , $l = 15\,cm$ , $\dot w = 4\,\frac{cm}{s}$ and $\dot l = 9\,\frac{cm}{s}$ , then the rate of change of the area of the rectangle is:

$\dot A = \dot w\cdot l + w\cdot \dot l$

$\dot A = 168\,\frac{cm^{2}}{s}$

The area of the rectangle is increasing at a rate of 168 square centimeters per second.

6 0

3 years ago

which Two labels could you place on a Triangle with no sides equal in length and one obtuse angle? 1 obtuse and acute 2 obtuse a

Pachacha [2.7K]

Answer: 3, "obtuse and scalene".

Step-by-step explanation:

Equilateral has all sides equal, eliminate 5.

Isosceles has two sides equal, eliminate 4.

Haven't seen the word scalene since 1966...

Sum of angles is 180°, right angle is 90°, obtuse angle is more than 90°, so there is no such thing as a right and obtuse triangle, eliminate 2. Think |_/.

Similarly, only one angle can be obtuse, think \_/, so every obtuse triangle has two acute angles. But I'm pretty sure "acute triangle" is defined to exclude triangles with an obtuse angle. In that case, "obtuse and acute" is contradictory. Eliminate 1.

That leaves 3, "obtuse and scalene." So now I remember a scalene triangle is one with all three sides different.

Wondering if that means all three angles are different. Yes, because if two angles are equal, the triangle has to be isosceles with base between the equal angles, roughly /_\, so two sides are equal.

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3 years ago