<span>1/r + 2/1-r = 4/r^2
1-r+2r/r(1-r)=4/r^2
(1+r)/r(1-r)=4/r^2 cancle r both side
1+r/1-r=4/r
cross multiply
r+r^2=4-4r
r^2+4r+r-4=0
r^2+5r-4=0
r^2+4r+r-4=0
solve it for r factor it...
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Answer: 68 degrees
Step-by-step explanation:
M∠A = 42° [isosceles triangle]
m∠B = 180 - 42 - 42 = 96° [in a triangle, the three interior angles always add to 180°]
m∠C = 180 - 96 - (x+12)
m∠C = 84 - x - 12
m∠C = 72 - x2x+9 + 3x-1 + 72-x = 180
4x + 80 = 180
4x = 180 - 80
4x = 100
x = 100/4
x = 25m∠C = 72 - x = 72 - 25 =
47°
<span>I hope this helped</span>
Answer:D
Step-by-step explanation: