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Pls help explain your thinking

Pls help explain your thinking-example-1

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Answer:

Mouse = 7

Hedgehog = 6

Owl = 4

Final equation = -2

Explanation:

Define the variables:

  • Let x = mouse.
  • Let y = hedgehog.
  • Let z = owl.

The variables in the second equation are the same. Therefore, begin with this equation to determine the value that the mouse represents (x):


\begin{aligned} \implies\sf Mouse + Mouse * Mouse + Mouse &=63\\ x+x * x+x&=63\end{aligned}

Following the order of operations, carry out the multiplication first:


\implies x+x^2+x=63

Add the like variables:


\implies x^2+2x=63

Subtract 63 from both sides:


\implies x^2+2x-63=0

Factor and solve for x:


\implies x^2+9x-7x-63=0


\implies x(x+9)-7(x+9)=0


\implies (x-7)(x+9)=0


\implies x-7=0 \implies x=7


\implies x+9=0 \implies x=-9

Therefore, the two possible values of the x are 7 and -9.

Evaluate the third equation where there are two variables:


\begin{aligned} \implies\sf Hedgehog * Hedgehog - Hedgehog + Mouse &=37\\ y * y-y+x&=37\end{aligned}

Carry out the multiplication first:


\implies y^2-y+x=37

Subtract 37 from both sides:


\implies y^2-y+x-37=0

As we have two possible values for x, substitute each value into the equation and solve for y.

Substitute x = 7 and solve for y:


\implies y^2-y+7-37=0


\implies y^2-y-30=0


\implies y^2-6y+5y-30=0


\implies y(y-6)+5(y-6)=0


\implies (y+5)(y-6)=0


\implies y+5=0 \implies y=-5


\implies y-6=0 \implies y=6

Substitute x = -9 and solve for y:


\implies y^2-y-9-37=0


\implies y^2-y-46=0

Using a calculator:


\implies y=(1 \pm √(185))/(2)

Assuming the numbers should be integers, we can discount x=-9 as it gives a non-integer value of y.

Therefore:

  • x = 7
  • y = -5 or y = 6

Evaluate the first equation where there are two variables:


\begin{aligned} \implies\sf (Hedgehog + Owl) * (Hedgehog - Owl)&=20\\ (y+z) *(y-z)&=20\end{aligned}

Simplify this equation and isolate z²:


\implies (y+z) * (y-z)=20


\implies y^2-zy+zy-z^2=20


\implies y^2-z^2=20


\implies z^2=y^2-20

As we have two possible values for y, substitute each value and solve for z.

Substitute y = -5 and solve for z:


\implies z^2=(-5)^2-20


\implies z^2=25-20


\implies z^2=5


\implies z=√(5)

Substitute y = 6 and solve for z:


\implies z^2=6^2-20


\implies z^2=36-20


\implies z^2=16


\implies z=4

Again, assuming the numbers should be integers, we can discount y=-5 as it gives a non-integer value of z. Therefore:

  • y = 6
  • z = 4

Therefore, we have determined that:

  • Mouse (x) = 7
  • Hedgehog (y) = 6
  • Owl (z) = 4

Substitute the found values into the fourth equation and solve:


\begin{aligned}\implies \sf Owl + Mouse - Hedgehog - Mouse &=z+x-y-x\\&=4+7-6-7\\&=11-6-7\\&=5-7\\&=-2\end{aligned}

User Geier
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