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Question 1:
Solve x2 = 24 – 10x?
A. 2, 8
B. 2, -12
Feedback Rewriting the equation into the standard quadratic form,
x2 +10x-24 = 0
What are the two numbers which when added give +10 and when multiplied give -24? 12 and -2.
So this can be solved by the factoring method. But let’s solve it using the new method, applying the quadratic formula.
Here, a = 1, b = 10 and c = -24.
x = [-10 ± √(100 – 4*1*-24)] / 2*1
x = [-10 ± √(100-(-96))] / 2
x = [-10 ± √196] / 2
x = [-10 ± 14] / 2
x = 2 or x= -12 are the roots.
C. 3, 8
D. 8, 5

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