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2 years ago

Solving systems equations by elimination

1 answer:

3 0

I won't answer them all for you (don't want to cheat - need to learn something).
But for the first one given:

<span>-2x-9y=-25
-4x-9y=-23

you set up either x or y (which ever one you want to eliminate) so that one of them cancels.
So this one is easy - you just have to multiply an entire row by negative (doesn't matter which one) - so that the y's will be + and -

Since they're both 9 and they're subracting NOW - you can eliminate the y value. Now add/subtract the x's. So it'd be -2 or 2 depending on how you eliminated y. Then add the number outside of the = sign. Now just solve for x. After that plug in whatever you got for x into both of the rows. Then find the y value.

Hopefully this wasn't confusing -- reply if it is and I will try to simplify. I can give you contact if you need help with the rest

Good luck!</span>

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Are the expressions -0.5(3x + 5) and<br> -1.5x + 2.5 equivalent? Explain why or why not.

Sedbober [7]

Answer:

No, because the first equation equals -1.5x + 2.5 when simplified, but when the second equation is simplified it equals 1

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2 years ago

Abe spent $144.00 for four bags of grass seed. How much did he spend on each bag

EastWind [94]

Answer:

Abe spent 36 dollars on each bag

Step-by-step explanation:

divide 144 by 4 (because there are 4 bags in total, and he spent 144 dollars)

the answer will be 36

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2 years ago

Read 2 more answers

Solve for x, y, and all of the missing angles. d = (2y+2) c = (3y + 18) a 50° b = (2x + 4) b degrees b degrees . degrees d = deg

CaHeK987 [17]

Answer:

that answer was wrong your dum

Step-by-step explanation:

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2 years ago

A farmer is tracking the amount of corn his land is yielding each year. He finds that the function f(x) = −x2 + 20x + 50 models

polet [3.4K]

Answer:

The crop yield increased by 9 pounds per acre from year 1 to year 10.

Step-by-step explanation:

To solve this we are using the average rate of change formula: $Av=\frac{f(x_2)-f(x_1)}{x_2-x_1}$ , where:

$x_2$ is the second point in the function

$x_1$ is the first point in the function

$f(x_2)$ is the function evaluated at the second point

$f(x_1)$ is the function evaluated at the first point

We know that the first point is 1 year and the second point is 10 years, so $x_1=1$ and $x_2=10$ . Replacing values:

$Av=\frac{-(10)^2+20(10)+50-[-(1)^2+20(1)+50]}{10-1}$

$Av=\frac{-100+200+50-[-1+20+50]}{9}$

$Av=\frac{150-[69]}{9}$

$Av=\frac{150-69}{9}$

$Av=\frac{81}{9}$

$Av=9$

Since $f(x)$ represents the number of pounds per acre and $x$ the number of years, we can conclude that the crop yield increased by 9 pounds per acre from year 1 to year 10.