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4 years ago

How would I solve this system of equations? 2y+x=-17 5x-4y=-15

1 answer:

3 0

$\left\{\begin{array}{ccc}2y+x=-17\\5x-4y=-15\end{array}\right\\\\\left\{\begin{array}{ccc}x+2y=-17&\text{multiply both sides by 2}\\5x-4y=-15\end{array}\right\\\\\underline{+\left\{\begin{array}{ccc}2x+4y=-34\\5x-4y=-15\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad7x=-49\qquad\text{divide both sides by 7}\\.\qquad\boxed{x=-7}\\\\\text{Put the value of x to the first equation:}\\\\2y+(-7)=-17\\2y-7=-17\qquad\text{add 7 to both sides}\\2y=-10\qquad\text{divide both sides by 2}\\\boxed{y=-5}\\\\Answer:\ \boxed{x=-7\ and\ y=-5\to(-7,\ -5)}$

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Kylie has lemon and watermelon in a ratio of 10:71. How many watermelon does she have if she has 20 lemons

kkurt [141]

Answer:

She will have 142 watermelons

Step-by-step explanation:

First let's put our ratio

10 : 71

Since our lemons are now 20 instead of 10 we will divide 20 by 10 to see how many time we multiplied it by.

$20 \div 10$

which equals 2

To find our water melon we will multiply it by 2

$71 \times 2$

which equals 142

She will have 142 watermelons

7 0

3 years ago

PLS ANSWER TODAY TYSM :p -5y+1-3y+2=-9

OLga [1]

We just combine the terms, like this:

-8y = -12

The answer is: y = 1.5 or 3/2.

Hope this helped! c:

7 0

3 years ago

The height of an ostrich is 20 inches more than 4 times the height of a kiwi. If an ostrich is 108 inches tall, how tall is a ki

blagie [28]

The answer would be (108-20)4=22

3 0

3 years ago

Read 2 more answers

Find the missing lengths: LO=5 and OK=4, find OH and KH.

hodyreva [135]

Answer:

The length of KH is 6 units and OH is 6.3 units.

Step-by-step explanation:

Given the figure with lengths LO=5 and OK=4. we have to find the length of OH and KH.

In ΔLOH

By Pythagoras theorem

$LH^2=LO^2+OH^2\\\\LH^2=5^2+OH^2$ → (1)

In ΔKOH,

$KH^2=OH^2+OK^2\\\\KH^2=OH^2+4^2$ → (2)

In ΔKHL,

$KL^2=LH^2+KH^2$

Using eq (1) and (2), we get

$KL^2=5^2+OH^2+OH^2+4^2$

$9^2=25+2OH^2+16$

⇒ $2OH^2=81-25-16=40$

⇒ $OH=\sqrt{20}=6.324\sim6.3units.$

Put the above value in eq 2, we get

$KH^2=20+4^2=36$

⇒ KH=6 units.

8 0

3 years ago

Read 2 more answers

The graph of the invertible function f is shown on the grid below What is the value of f^-1(6)

dolphi86 [110]

Given:

The graph of an invertible function $f$ is given.

To find:

The value of $f^{-1}(-3)$ .

Solution:

We know that, if the graph of an invertible function $f$ passes through the point (a,b), then the inverse function $f^{-1}$ passes through the point (b,a).

From the given graph it is clear that the graph of the function $f$ passes through the points $(-5,-3)$ .

So, the inverse function $f^{-1}$ must be passes through the point $(-3,-5)$ .

Therefore, the value of inverse function is $-5$ at $x=-3$ . So, the value of $f^{-1}(-3)$ is $-5$ .

8 0

3 years ago