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3 years ago

Solve the system: 4x - y = 5 x + 2y = 8

Mathematics

2 answers:

77julia77 [94]3 years ago

6 0

Answer:

Step-by-step explanation:

4x - y = 5..........… Equation 1

x + 2y = 8 ............. Equation 2

Make x the subject in equation 2 and substitute it into equation 1

That's

x = 8 - 2y

We have

4( 8 - 2y ) - y = 5

32 - 8y - y = 5

- 9y = - 27

Divide both sides by - 9

We have the final answer as

Substitute y = 3 into x = 8 - 2y

That's

x = 8 - 2(3)

= 8 - 6

Hope this helps you

aleksley [76]3 years ago

6 0

Step-by-step explanation:

4x-y=5-----×1.

x+2y=8----×4.

which will be....

4x-y=5

- 4x+8y=32.

____________

-9y=-27

----- ----

-9. -9.

y=3.

then substitute into any equation...

equation one.

4x-3=5.

4x=5+3.

4x=8.

x=8/4.

x=2.

therefore y=3 and x=2.

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soldi70 [24.7K]

Answer:

-1

Step-by-step explanation:

-(-4)-5=

4-5=

-1

8 0

3 years ago

Read 2 more answers

8) through: (-3, -2), perp. to y = x – 1<br> A) y=-5x – 1 B) y=-4x – 5<br> C) y=-x – 5 D) y=-5x – 4

nexus9112 [7]

<u>Answer:</u>

The equation through (-3, -2) and perpendicular to y = x – 1 is y = -x -5 and option c is correct.

<u>Solution:</u>

Given, line equation is y = x – 1 ⇒ x – y – 1 = 0. And a point is (-3, -2)

We have to find the line equation which is perpendicular to above given line and passing through the given point.

Now, let us find the slope of the given line equation.

$\text { Slope }=\frac{-x \text { coefficient }}{y \text { coefficient }}=\frac{-1}{-1}=1$

We know that, <em>product of slopes of perpendicular lines is -1. </em>

So, 1 $\times$ slope of perpendicular line = -1

slope of perpendicular line = -1

Now let us write point slope form for our required line.

$\mathrm{y}-\mathrm{y}_{1}=\mathrm{m}\left(\mathrm{x}-\mathrm{x}_{1}\right)$

y – (-2) = -1(x – (-3))

y + 2 = -1(x + 3)

y + 2 = -x – 3

x + y + 2 + 3 = 0

x + y + 5 = 0

y = -x -5

Hence the equation through (-3, -2) and perpendicular to y = x – 1 is y = -x -5 and option c is correct.

8 0

4 years ago

If the if a cylinder is 7 in tall and has a volume of 63 Pi inches what is the area of the cross section it goes right down the

vitfil [10]

Answer: $9\pi \ in.^2$

Step-by-step explanation:

Given

The height of the cylinder is $h=7\ in.$

The volume of the cylinder is $V=63\pi \ in.^3$

The volume of the cylinder is the product of area and height

$\Rightarrow V=\pi r^2h\\$

Insert the values

$\Rightarrow 63\pi =A\times 7\\\\\Rightarrow A=\dfrac{63\pi}{7}\\\\\Rightarrow A=9\pi\ in.^2$

Thus, the area of the cross-section is $9\pi \ in.^2$

7 0

3 years ago

Consider the original complex figure and the reduction.

Dmitriy789 [7]

Answer:

1/8

Step-by-step explanation:

I'm going to try to explain this as easy as possible. What I did was take the original shape and divide it by the new shape. For this question, I solved it by dividing 32(the original base) by 4(the new base) and got 8. So the scale factor of the reduction was 1/8.

8 0

3 years ago

A quadratic equation has a

11111nata11111 [884]

Answer:

$\boxed {\boxed {\sf 2 \ real \ solutions }}$

Step-by-step explanation:

The quadratic formula is:

${x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}}$

The discriminant of a quadratic is just the expression under the square root, or $b^2-4ac$ . This can tell us the number of solutions a quadratic has.

If the discriminant is:

Positive = 2 real solutions
Equal to Zero = 1 real double/repeated solution
Negative = 0 real solutions, but 2 imaginary solutions

Our quadratic equation has a discriminant of 5, which is positive. Therefore, it has 2 real solutions.

6 0

3 years ago