This is an important test please help.
2 answers:
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Answer:
x= -2 or x= 8
Step-by-step explanation:
First step, move 25 to the left side so we can do the Quadratic Formula (or you can factor instead.)
Next, we know that 9-25 equals -16.
Now find that what two numbers multiply and get 16: 2×8 4×4 and 16×1.
Now we do some kind of factoring. The most valuable number must be negative since -6x is negative.
Let's explain about factoring in Quadratic a little bit.
Substitue x²-6x-16 as ax²+bx+c=0
From (ax+d)(bx+c), if we multiply ax and bx, we get the ax²
If we multiply ax and c, we get acx and we multiply d and bx, we get dbx. (axc+bdx) = bx
If we multiply d and c, we get c.
From the factor lf 16, 2×8 seems to be right since -8+2 equals -6 which matches the equation.
Then we get.
Seperate both equations.
Find the value of both x.
The answer is x = -2, 8
(The explanation might be weird since I don't know what they are called in English.)