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For what values of x is x2 + 2x = 24 true?

2 Answers

6 votes
x²+2x=24
Subtract 24 to each side
x²+2x-24=24-24
x²+2x-24=0
Factor thus with
ax²+mx+nx+b
0=x²+6x-4x-24
0=x(x+6)-4(x+6)
0=(x-4)(x+6)
x-4=0
Add 4 to each side
x-4+4=0+4
x=4

x+6=0
Subtract 6 to each side
x+6-6=0-6
x=-6. As a result, x could equal to 4 and -6. Hope it help!
User Prajwal Gonsalves
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8.4k points
4 votes
x² + 2x = 24

Organizing:
x² + 2x - 24 = 0
<<<< (Quadratic equation)

Delta:
Δ = b² - 4.a.c
Δ = 2² - 4 * 1 * -24
Δ = 4 - 4 * 1 * -24
Δ = 100

Bhaskara:
x = (-b +- √Δ)/2*a

x' = (-2 + √100)/2*1
x' = 8 / 2
x' = 4

x'' = (-2 - √100)/2*1
x'' = -12 / 2
x'' = -6

Result: x = 4 or x = - 6 .

Good studies! :)
User XGHeaven
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8.4k points

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