Ellie is 5 times as old as her sister Emma. In 2 years Ellie will be 3 times as Emma. How old is Emma now?

Mathematics

1 answer:

cricket20 [7]2 years ago

5 0

Answer:

8 years old maybe.

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Write the equation of the line through (-2,1) and parallel to y= -3x+1

DedPeter [7]

Use point slope equation y-y1=m(x-x1) Remember that a parallel line has the same slope.

y-1= -3(x-(-2))
y-1= -3(x+2)
y-1= -3x-6
y= -3x-5

Final answer: y=-3x-5

7 0

2 years ago

If the second number is subtracted from the sum of the first number and 2 times the third number, the result is 1. The thrid num

weeeeeb [17]

Answer:

Step-by-step explanation:

$x,\ y,\ z-\text{three numbers}\\\\\left\{\begin{array}{ccc}(x+2z)-y=1&(1)\\z+2x=3&(2)\\x+3y+z=18&(3)\end{array}\right\\\\(2)\\z+2x=3\qquad\text{subtract}\ 2x\ \text{from both sides}\\z=3-2x\qquad(*)\\\\\text{Substitute}\ (*)\ \text{to (1) and (3)}\\\\\left\{\begin{array}{ccc}x+2(3-2x)-y=1&\text{use the distributive property}\\x+3y+(3-2x)=18\end{array}\right$

$\left\{\begin{array}{ccc}x+(2)(3)+(2)(-2x)-y=1\\x+3y+3-2x=18&\text{subtract 3 from both sides}\end{array}\right\\\left\{\begin{array}{ccc}x+6-4x-y=1&\text{subtract 6 from both sides}\\(x-2x)+3y=15\end{array}\right\\\left\{\begin{array}{ccc}(x-4x)-y=-5\\-x+3y=15\end{array}\right\\\left\{\begin{array}{ccc}-3x-y=-5&\text{multiply both sides by 3}\\-x+3y=15\end{array}\right$

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