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3 years ago

How do i solve using the substitution method? x+y=-1 y=-2x

Mathematics

2 answers:

4vir4ik [10]3 years ago

8 0

Answer:

(1,-2)

Step-by-step explanation:

x+y=-1

y=-2x

substitute the value of y into an equation

x-2x=-1

minus the x and -2x

-1x=-1

divide both sides by -1

x=1

substitute the value of x into an equation

y=-2*1

multiply -2 and 1

y= -2

(1, -2)

leonid [27]3 years ago

4 0

Answer:

$(1, -2)$

Step-by-step explanation:

<u>Step 1: Set the second equation into the first </u>

$x + (-2x) = -1$

$x - 2x = -1$

$-x / -1 = -1 / -1$

$x = 1$

<u>Step 2: Solve the second equation </u>

$y = -2(1)$

$y = -2$

Answer: $(1, -2)$

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How do I solve this?

andreev551 [17]

Answer:

x is in the range [-1,4]

Step-by-step explanation:

I haven't worked with absolute value inequalities in awhile, but let's take a wack at this.

We are given the following inequality:

| 2x - 3 | <= 5

This implies two possible cases:

[1] -5 <= 2x -3

[2] 2x - 3 <= 5

So let's solve x for both of these cases:

[1] -5 <= 2x - 3

-2 <= 2x

-1 <= x

[2] 2x - 3 <= 5

2x <= 8

x <= 4

So from these cases, we can say the following is true:

x >= -1 and x <= 4

Thus, we can write this in the form

-1 <= x <= 4

Or in interval notation:

{ x is element of reals | -1 <= x <= 4}

Also written as

x is in the range [-1,4]

Where the closed brackets represent 1 and 4 as possible answers whereas parenthesis would imply they were not.

Cheers.

4 0

3 years ago

Your bank account is sitting on $14,000. You started with a principal balance of $12,500. If the interest rate was 4.5% compound

Simora [160]

Answer:

$t=2.5\ years$

Step-by-step explanation:

we know that

The formula to calculate continuously compounded interest is equal to

$A=P(e)^{rt}$

where

A is the Final Investment Value

P is the Principal amount of money to be invested

r is the rate of interest in decimal

t is Number of Time Periods

e is the mathematical constant number

we have

$t=?\ years\\ P=\$12,500\\P=\$14,000\\ r=4.5\%=4.5/100=0.045$

substitute in the formula above and solve for t

$14,000=12,500(e)^{0.045t}$

Simplify

$14,000/12,500=(e)^{0.045t}$

$1.12=(e)^{0.045t}$

Apply ln both sides

$ln(1.12)=ln[(e)^{0.045t}]$

$ln(1.12)=(0.045t)ln(e)$

Remember that

$ln(e)=1$

$ln(1.12)=(0.045t)$

$t=ln(1.12)/(0.045)$

$t=2.5\ years$

3 0

3 years ago

I am in need of assistance

vivado [14]

1. To find the x-intercept, replace y in the equation with 0, then solve for x.

... To find the y-intercept, replace x in the equation with 0, then solve for y.

If the equation is easily put into the form

... x/a + y/b = 1

Then the x-intercept is "a" and the y-intercept is "b".

2. Let's graph 3x+4y = -12.

If we divide the equation by -12, we can put it into the form

.. x/(-4) + y/(-3) = 1

This equation has x-intercept -4 and y-intercept -3.

(If you know the intercepts, you can simply draw the line through them to graph your linear equation.)

3 0

2 years ago

What are the solutions of the system 7x + 3y = -3 and y = -2 x ?

saul85 [17]

I am assuming that the second equation is $y = -2^x$ . In that case, the correct answers are (0, -1) and (3, -8).

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3 years ago

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N76 [4]

Answer:

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Step-by-step explanation:

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2 years ago

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