Help please!! 20 points and brainliest!!

1 answer:

4 0

Alright, so we have
<span>-9x+6y=-30
</span><span>-12x+9y=-30

Although we might really want to say -9x+6y=-12x+9y, we can't do it that way. We have to get rid of a variable and go from there. Solving for y, we get
</span>-9x+6y=-30
Divide both sides by 3
-3x+2y=-10
Add 3x to both sides
2y=-10+3x
Divide both sides by 2
y=(-10+3x)/2

-12x+9y=-30
Divide both sides by 3
-4x+3y=-10
Add 4x to both sides
-10+4x=3y
Divide both sides by 3
(-10+4x)/3=y

Since we have
(-10+4x)/3=y and y=(-10+3x)/2 , we have
(-10+4x)/3=(-10+3x)/2
Since 3*2=6, we can multiply both sides by 6
-20+8x=-30+9x
Add 30 to both sides
10+8x=9x
Subtract 8x from both sides
x=10
Plug that in to any equation,and you should have your answer! Good luck, and ask if you have any questions!

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y - number of motorcycles

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Please please help me

Gekata [30.6K]

Answer:

$\large\boxed{\dfrac{\boxed{8}}{81}}$

Step-by-step explanation:

$\text{If}\ a_1,\ a_2,\ a_3,\ a_4,\ ...,\ a_n\ \text{is the geometric sequence, then}\\\\\dfrac{a_2}{a_1}=\dfrac{a_3}{a_2}=\dfrac{a_4}{a_3}=...=\dfrac{a_n}{a_{n-1}}=constant=r-\text{common ration}.\\\\\text{We have}\ \dfrac{1}{2},\ \dfrac{1}{3},\ \dfrac{2}{9},\ \dfrac{4}{27},\ ...\\\\\dfrac{\frac{1}{3}}{\frac{1}{2}}=\dfrac{1}{3}\cdot\dfrac{2}{1}=\dfrac{2}{3}\\\\\dfrac{\frac{2}{9}}{\frac{1}{3}}=\dfrac{2}{9}\cdot\dfrac{3}{1}=\dfrac{2}{3}\\\\\dfrac{\frac{4}{27}}{\frac{2}{9}}=\dfrac{4}{27}\cdot\dfrac{9}{2}=\dfrac{2}{3}$

$\bold{CORRECT}\\\\\dfrac{x}{\frac{4}{27}}=\dfrac{2}{3}\qquad\text{multiply both sides by}\ \dfrac{4}{27}\\\\x=\dfrac{2}{3}\cdot\dfrac{4}{27}\\\\x=\dfrac{8}{81}$

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