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Elenna [48]
2 years ago
7

Solve the system of equations by the addition method.

Mathematics
2 answers:
Eva8 [605]2 years ago
8 0

\left \{ {{\frac{x}{2}-y=7 } \atop {-\frac{x}{7}+\frac{2y}{7}= -2 }} \right. \left \{ {{\frac{x}{2}.2-2y=2.7} \atop {-\frac{x}{7}.7+\frac{2y}{7}.7= -2.7}} \right. \left \{ {{x-2y=14} \atop {-x+2y=-14}} \right. \left \{ {{0x=0} \atop {y={\frac{x}{2}-7}} \right.

ANSWER: B

ok done. Thank to me :>

larisa [96]2 years ago
7 0

Integer solution

x= 2n, y=n-7, nEZ

real solution    or you can use inverse operation to have addition

y= x/2-7               y=x[multiplied by] 2+7

oh and for the first one the choice is A the second one im sorry im not sure

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Answer with explanation:

Using following law of indices

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9. (4\times x\times y^2)^3\times (xy)^5=4^3\times x^3\times (y^2)^3\times x^5 \times y^5\\\\=64\times x^{3+5}\times y^{5+6}\\\\=64x^8y^{11}\\\\10.(2\times t^3)^3(0.4\times r)^2=2^3 \times (t^3)^3\times (0.4)^2 \times r^2=8\times t^9 \times 0.16 \times r^2=1.28r^2t^9

8. A number raised to a negative exponent is negative.

Explaining with the help of few examples

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2.Option A

3.Option C

4.Option A

5.Option D

6.  81 \times 10^6

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So, to get the percent increased:

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