Nouvelle formation ! Tous les codeurs devraient apprendre l'IA générative !
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# (1+?)**2=16

5th Oct 2019, 10:39 AM
Akrem Barboura
3 Réponses
+ 3
Hint: use the inverse operation of squaring a number.
5th Oct 2019, 10:43 AM
Michael
+ 2
(1+x)**2 = 16 (1+x)*(1+x) = 16 1+x+x+x^2 =16 x^2 + 2x + 1=16 |-16 x^2 + 2x - 15 = 0 pq-formula: -2/2 +- √((2/2)^2-(-15)) <=> -1 +- √((1)+15) <=> -1 +- √(16) Now you have two solutions: X1= -1 + √(16) = 3 X2= -1 - √(16) = -5 proove that solutions X1,2 are right: X1: (3)^2 + 2(3) - 15 = 0 15 - 15 = 0 X2: (-5)^2 + 2(-5) - 15 = 0 25 - 25 = 0
5th Oct 2019, 1:28 PM
William M
0
When: x = y You need to think, that x is y, what ever changes you do on x, you can do for y, and their results are equal: x + a = y + a x - b = y - b x*a*b = y*a*b √x = √y x+x = y+x x**2 = y**2 (There is an exception that you should not multiply or divide by 0.) When you want to solve a variable, (in your question it is "?"), you want do operations (on both sides), so that in 1 side there would only be the variable we want to solve. (10 + ?) ** 2 = 64 We can take squareroot from both sides to simplify the expression: (10 + ?) ** 2 = 64 ||√(...) √((10 + ?) ** 2) = √(64) 10 + ? = (+/-) 8 (+/-) 8 meand that 8 can be positive or negative, squareroot √(x) means what multiplied by what equals x, because (-8)*(-8) = 64 and 8*8 = 64, we don't know whether the squareroot is negative or positive. But now we can subtract 10 from both sides: 10 + ? = (+/-) 8 ||-10 10 + ? - 10 = (+/-) 8 - 10 ? = (+/-) 8 - 10 And ? can either be: ? = +8 - 10 = -2 or: ? = -8 - 10 = -18
5th Oct 2019, 12:50 PM
Seb TheS
Aujourd'hui en vedette
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