7(x - 3) = 4(x + 5)
7x - 21 = 4x + 20
7x - 4x = 20 + 21
3x = 41
x = 41/3
(x - 3) - 2(x + 6) = -5
x - 3 - 2x - 12 = -5
-3x - 15 = -5
-3x = -5 + 15
-3x = 10
x = -10/3
multiply the x and y coordinates in P and Tand equate it the right hand side x and y coordinates respectively.
The temp. started at -20. If it rose +8 degrees, then it would be -20+8=-12, because since the -20 and +8 are opposites, you would subtract them and the answer would have the sign of the larger number which is -. so -12 is the answer.

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Factorise a² - b² :
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Crossed out common factors, (x + a) :
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The answer is C! Hope this helps!