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3 years ago

PLEASE HELP WILL GIVE BRAINLIEST!!!!!

Mathematics

1 answer:

Ilya [14]3 years ago

8 0

Mark the two equations below as A and B,

A: 3x+y=4

B: 2x+y=7

Because there's a y for both A and B, elimination (or linear combination, depending on the book) works well. If we add both equations we get 2y for the y terms. What if we subtracted instead. y - y = 0, and we eliminate the y terms. For subtracting, we multiply B by -1.

3x + y = 4

-2x - y = -7

Adding both equations (remember to change the signs on B) gives that 1x = -3 and so x = -3.

Now we take x = -3 and put into an original equation. Let's go into A.

3x+y=4

3 * -3 + y = 4 letting x = -3

-9 + y = 4

y = 13 adding 9 on both sides

So x = -3 and y = 13, or the ordered pair (-3, 13) - the 2nd one given - is our solution.

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Given a triangle with angles of 23°, 90°, 67°.

marishachu [46]

The answer is that it's a right triangle. One angle is 90°

8 0

3 years ago

Pls help me with this

astra-53 [7]

Answer:

the third one!

Step-by-step explanation:

Because it says, the SUM of the number, x (or z I can't really see it well) and 1/2, you must add those two together:

1/2 + x

Then it says those two numbers equal to 4, so it would look like this:

1/2 + x = 4

Because you are trying to isolate, and solve for x, you must SUBTRACT 1/2 from both sides of the equal sign:

1/2 + x = 4

-1/2 -1/2

1/2 minus 1/2 would result 0, so there would be x by itself. and 4 minus 1/2 would be 3 and a half ( 3 1/2), so x would be 3 1/2

x = 3 1/2

Hope this helped. If this is incorrect please specify so I can help :)

7 0

3 years ago

McDonald's is the king of the burger world, as it has more hamburger joints than any other restaurant chain. In 2013, McDonald's

fgiga [73]

It is given that in 2013, McDonald's had 14267 locations in the US. It is also given that the population of the US was approximately 316.5 million citizens in 2013. Now, we know that 316.5 million=316500000.

Therefore, in order to find the number of McDonald's restaurants per capita in the US in 2013 all that we have to do is divide the number of McDonald's restaurants in 2013 with the population of the same year.

Thus, we get, number of McDonald's restaurants per capita in the US in 2013 to be:

$\frac{14267}{316500000}\approx4.508\times10^{-5}$ (the answer has been expressed in scientific notation rounded correctly to three decimal) places.

8 0

3 years ago

Read 2 more answers

Henry predicted whether he got answers right or wrong in his 50 question exam. He identified the 36 questions he thought he got

Paha777 [63]

Answer:

84%

Step-by-step explanation:

Henry completed a total of 50 questions. From these 50 he predicted 36 were right and this means he also predicted that 14 were wrong (50-36 = 14). From these predictions 5 out of 36 from the ones that he predicted were right were actually wrong and 3 of the 14 questions (14-11 = 3) he predicted were wrong were actually right. Meaning in total he wrongly predicted 8 questions which means he predicted 42 correctly ...

42 / 50 = 0.84 = 84%

Therefore, Henry's prediction accuracy is 84%

6 0

3 years ago

A store is having a sale on walnuts and chocolate chips. For 3 pounds of walnuts and 2 pounds of chocolate chips, the total cost

Lena [83]

Answer:

$9.75

Step-by-step explanation:

A store is having a sale on walnuts and chocolate chips. For 3 pounds of walnuts and 5 pounds of chocolate chips, the total cost is $16. For 6 pounds of walnuts and 2 pounds of chocolate chips, the total cost is $22

. Find the cost for each pound of walnuts and each pound of chocolate chips.

***

let x=cost/lb of walnuts

let y=cost/lb of chocolate chips

3x+5y=16

6x+2y=22

6x+10y=32 (mult. eq by 2)

6x+2y=22

subtract:

8y=10

y=10/8=1.25

x=16-5y=9.75

cost/lb of walnuts=$1.25

cost/lb of chocolate chips=$9.75

7 0

3 years ago