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3 years ago

Use the elimination method to solve the system of equations. Choose the

Mathematics

1 answer:

guajiro [1.7K]3 years ago

5 0

Answer:

The correct answer is D. (1,6)

Step-by-step explanation:

When plugged into the equations, it is written 10(1) + 2(6) = 22 and 3(1) - 4(6) = -21. For the first one, 10 x 1 = 10 and 2 x 6 = 12. 10 + 12 = 22. For the second one, 3 x 1 = 3 and 4 x 6 = 24. 3 - 24 = -21. This makes both equations correct, making (1,6) the answer.

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How do I find x in this problem?

torisob [31]

Answer:

(6-2)×180 = 720

101+154+72+123+145+x=720

595 + x = 720

x = 720-595

x= 125

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2 years ago

One pint of blueberries contains about 80 berries. Lee's fruit salad recipe calls for 20 blueberries per serving. She has all of

DanielleElmas [232]

80
One pint of blueberries contains about 80 berries. Lee's fruit salad recipe calls for 20 blueberries per serving. She has all of the other fruit necessary for the salad, but only 1 quart of blueberries. How many servings of the fruit salad can Lee prepare?

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3 years ago

determine the point of intersection of the following pair of lines ............2x-3y-4=-13 and 5x=-2y+25. 3x+2y-7=0 and 2x=12-5y

grandymaker [24]

Answer:

(x, y) = (3, 5)
(x, y) = (1, 2)

Step-by-step explanation:

A nice graphing calculator app makes these trivially simple. (See the first two attachments.) It is available for phones, tablets, and as a web page.

The usual methods of solving a system of equations involve elimination or substitution.

There is another method that is relatively easy to use. It is a variation of "Cramer's Rule" and is fully equivalent to elimination. It makes use of a formula applied to the equation coefficients. The pattern of coefficients in the formula, and the formula itself are shown in the third attachment. I like this when the coefficient numbers are "too messy" for elimination or substitution to be used easily. It makes use of the equations in standard form.

_____

1. In standard form, your equations are ...

2x -3y = -9
5x +2y = 25

Then the solution is ...

$x=\dfrac{-3(25)-(2)(-9)}{-3(5)-(2)(2)}=\dfrac{-57}{-19}=3\\\\y=\dfrac{-9(5)-(25)(2)}{-19}=\dfrac{-95}{-19}=5\\\\(x,y)=(3,5)$

2. In standard form, your equations are ...

3x +2y = 7
2x +5y = 12

Then the solution is ...

$x=\dfrac{2(12)-5(7)}{2(2)-5(3)}=\dfrac{-11}{-11}=1\\\\y=\dfrac{7(2)-12(3)}{-11}=\dfrac{-22}{-11}=2\\\\(x,y)=(1,2)$

_____

Note on Cramer's Rule

The equation you will see for Cramer's Rule applied to a system of 2 equations in 2 unknowns will have the terms in numerator and denominator swapped: ec-bf, for example, instead of bf-ec. This effectively multiplies both numerator and denominator by -1, so has no effect on the result.

The reason for writing the formula in the fashion shown here is that it makes the pattern of multiplications and subtractions easier to remember. Often, you can do the math in your head. This is the method taught by "Vedic maths" and/or "Singapore math." Those teaching methods tend to place more emphasis on mental arithmetic than we do in the US.

7 0

3 years ago

Jade buys a blouse and a skirt for 3/4 of their original price. Jade pays a total of $31.50 for the two items. If the original p

Norma-Jean [14]

3/4 times 18= 13.5
31.5-13.5=18
It cost 18 dollars for the skirt with a discount.
It cost 13.5 for the blouse as opposed to the original price of 18 dollars.
18(skirt)+13.5(blouse)=31.5
If you set up a proportion to find the original price of the skirt you will get the answer.
18/x=75/100
75x=18 times 100
75x=1800
75x/75=1800/75
x=24
The original price of the skirt is 24 dollars.

7 0

3 years ago

WILL MARK BRAINLIEST!!! What is the exact value of tan(−3π4) ?

Hoochie [10]

Answer:

-12π

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers