Mathematics, 16.09.2020 05:01 ozzy1146

8x+4y=-20
6x+6y=-18

-7x+7y=-21
4x-2y=22

Answers: 2

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Answers

8x + 4y = -20 ⇒ 24x + 12y = -60
6x + 6y = -18 ⇒ 12x + 12y = -36
      12x = -24
   12 12
      x = -2
      8x + 4y = -20
      8(-2) + 4y = -20
      -16 + 4y = -20
      + 16 + 16
   4y = -4
      4     4
   y = -1
   (x, y) = (-2, -1)

-7x + 7y = -21 ⇒ -14x + 14y = -42
4x - 2y = 22 ⇒   28x - 14y = 154
      14x = 112
   14 14
      x = 8
         -7x + 7y = -21
      -7(8) + 7y = -21
      -56 + 7y = -21
      + 56 + 56
   7y = 35
7    7
   y = 5
       (x, y) = (8, 5)

Answer from: Quest

34.5 cm

step-by-step explanation:

generally for a circular segment of angle, θ° and radius r

arc length

= (θ/360) x circumference

= (θ/360) x 2πr

in our case, θ = 60°, π=3.142 and r = 33 cm

substitute into above formula

arc length

= (60/360) x 2(3.142)( 33) = 34.5 cm

Answer from: Quest

isocolese triangle

we know that the line connect a and b is the hyptonuse

so first find the hypotonuse length using the distance formula, call the length c

since it is an isocolese triangle, the lengths of the legs are the same

using pythagorean theorem, $a^2+b^2=c^2$

in this case, a=b since isocolese triangle so we get

$2a^2=c^2$ or $a=\frac{c}{\sqrt{2}}$

we can find c so we can find the distances

we know that if we draw 2 circles, each has center at a and b, and find where they intersect, we can the 2 possible locations for c

if a has center at (xa,ya) and b has center at (xb,yb), then we can solve where

$(x-x_a)^2+(y-y_a)=(\frac{c}{\sqrt{2}})^2$ and

$(x-x_b)^2+(y-y_b)^2=(\frac{c}{\sqrt{2}})^2$ intersect to find where they intersect

i'm not going to put an example because i have to go to class. i hope this explanation is enough

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8x+4y=-20
6x+6y=-18

-7x+7y=-21
4x-2y=22...

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