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Gala2k [10]
2 years ago
13

Write a system of equations to describe the situation below, solve using elimination.

Mathematics
1 answer:
Sedbober [7]2 years ago
8 0

Answer:

The cost of hardbook is $9 and cost of paperback is $5.

Step-by-step explanation:

Let x be the price for hardback book and y be the price for paperback book.

Mr. Yamamoto purchased 42 new hardcover books and 64 new paperback books, which cost a total of $698.

We can write the equation as:

42x + 64y = 698

He also purchased 42 new hardcover books and 58 new paperback books, which cost a total of $668.

We can write the equation as:

42x + 58y = 668

We have to use the elimination method to solve the two equations.

We eliminate x by subtracting the two equations.

42x + 64y-(42x + 58y) = 698 - 668\\\Rightarrow 6y = 30\\\Rightarrow y = 5\\42x + 64(5) = 698\\\\\Rightarrow x = \displaystyle\frac{698 - 64(5)}{42}\\\\\Rightarrow x = 9

Thus, the cost of hardbook is $9 and cost of paperback is $5.

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The product of the roots of the equation x2 + x=2 is:<br> 0-2<br> 01
gregori [183]

Answer:

-2

Step-by-step explanation:

x^2 + x=2

Subtract 2 from each side

x^2 + x-2=2-2

x^2 + x-2=0

Factor

What 2 numbers multiply to -2 and add to 1

2*-1 = -2

2+-1 =1

(x-1)(x+2)=0

Using the zero product property

x-1 = 0  x+2 = 0

x=1        x = -2

Product of the roots

1*-2 = -2

5 0
2 years ago
-4x + 7 is greater than or equal to 83<br> (sorry, i couldn't get the sign for it)
bezimeni [28]

Answer:

-19

Step-by-step explanation:

you first substract 7 from 83 since its the inverse operation

then you divide it by -4 which give you -19

4 0
2 years ago
Help pls do allll 6 questions... with steps
BaLLatris [955]
You just want to simplify right?!

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48. -10g^6h^9(g^2h^3) / 30g^3h^3
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5 0
2 years ago
What is y=4x^2-9x+1 in vertex form
Anna11 [10]

Answer:

y = 4 \left(x - \dfrac{9}{8} \right)^2 - \dfrac{65}{16}

Step-by-step explanation:

y = 4x^2 - 9x + 1

You need to complete the square on the right side.

y = (4x^2 - 9x) + 1

y = 4(x^2 - \dfrac{9}{4}x) + 1

y = 4 \left( x^2 - \dfrac{9}{4}x + \left( \dfrac{9}{8} \right)^2 \right) + 1 - 4\left( \dfrac{9}{8} \right)^2

y = 4 \left(x - \dfrac{9}{8} \right)^2 + 1 - 4 \left( \dfrac{81}{64} \right)

y = 4 \left(x - \dfrac{9}{8} \right)^2 + 1 - \dfrac{81}{16}

y = 4 \left(x - \dfrac{9}{8} \right)^2 + \dfrac{16}{16} - \dfrac{81}{16}

y = 4 \left(x - \dfrac{9}{8} \right)^2 - \dfrac{65}{16}

3 0
2 years ago
A cube has a surface area of 486 square meters.<br><br> Find the volume of the cube.
joja [24]
486/6=81
Square root 81 = one side length = 9m
volume = 9^3 = 729
7 0
3 years ago
Read 2 more answers
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