Mathematics, 05.10.2019 12:00 gajdmaciej9502

Select the best possible first step to solving the system by first eliminating the x variable. 4x 9y = 21 3x − 8y = 1 multiply the first equation by 3, and multiply the second equation by 4. multiply the first equation by −3, and multiply the second equation by −4. multiply the first equation by 8, and multiply the second equation by 9. none of the above

Answers: 2

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Answer from: Oregonduckerz

Multiply the first equation by 3, and multiply the second equation by 4.

Answer from: kenzierosa

The correct option is

(A) multiply the first equation by 3, and multiply the second equation by 4.

Step-by-step explanation: The given system of linear equations is:

$4x+9y=21~~~~~~~~~~~~~~~~(i)\\\\3x-8y=1~~~~~~~~~~~~~~~~~(ii)$

We are to select the best possible first step to solve the above system by first eliminating x variable.

Since, we need to eliminate x variable first, so will try to make the coefficients of x in both the equations equal. After that, we will subtract one of the equations from the other to eliminate x.

The co-efficient of x in equation (i) is 4,

and

the co-efficient of x in equation (ii) is 3.

So, to make both of them same, we will take the LCM of the coefficients 4 and 3.

We have

LCM(4, 3) = 12.

Now, we will multiply equation (i) by 3 and equation (ii) by 4 to make both the coefficients in equation (i) and (ii) equal to 12.

Thus, we will multiply first equation by 3 and second equation by 4.

Option (A) is CORRECT.

Answer from: Quest

sinn is the total amount of students now and m were the students before, you subtract them both (n-m) and divide that by m. then, since to get a percentage from a fraction you have to multiply by 100, your answer should look like this: n-m/m*100

step-by-step explanation:

Answer from: Quest

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

$a=9\times 12=108\text {ft^2}$

so the area of the floor is 108 square feet, converting that into square yards we get,

$108 \times 0.1111= 12 \text{yd^2}$

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

$\$15 \times 12=\$180$

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

$a = 12 \times 15=180\text {ft}^2$

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

$180 \times 0.111=20 \text {yd}^2$

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

$\$15 \times 20= \$300$

so, it will cost $300.

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Select the best possible first step to solving the system by first eliminating the x variable. 4x 9y...