For x + 2 squared to equal 4 squared, x + 2 can equal either 4 or -4:
x + 2 = 4 ==> x = 2
x + 2 = -4 ==> x = -6
Check:
(2 + 2)^2 = 4^2 = 16
(-6 + 2)^2 = (-4)^2 = 16
x + 2 = 4 ==> x = 2
x + 2 = -4 ==> x = -6
Check:
(2 + 2)^2 = 4^2 = 16
(-6 + 2)^2 = (-4)^2 = 16
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Here are 3 ways to approach this:
➊ 4² = (x+2)² ... Notice that both 4 and (x+2) are squared and that (x+2) can be
either positive or negative so that 4² = (x+2)² implies that 4 = ±(x+2).
4 = ±(x+2)
4 = +(x+2) OR 4 = -(x+2)
2 = x 4 = -x -2
x = 2 OR x = -6
ANSWER
x = -6, 2
➋ 4² = (x+2)² ... Take the square root of both sides.
√(4²) = √( (x+2)² ) ← √(u²) = │u│for all real numbers u
4 = │x+2│
±4 = x+2 ← If │u│=a, then u = ±a
-2 ± 4 = x
2, -6 = x ← ANSWER
➌ 4² = (x+2)² ... Expand
16 = x² + 4x + 4
0 = x² + 4x - 12
0 = (x+6)(x-2)
x= -6, x=2 ← ANSWER
——————————————————————————————————————
Here are 3 ways to approach this:
➊ 4² = (x+2)² ... Notice that both 4 and (x+2) are squared and that (x+2) can be
either positive or negative so that 4² = (x+2)² implies that 4 = ±(x+2).
4 = ±(x+2)
4 = +(x+2) OR 4 = -(x+2)
2 = x 4 = -x -2
x = 2 OR x = -6
ANSWER
x = -6, 2
➋ 4² = (x+2)² ... Take the square root of both sides.
√(4²) = √( (x+2)² ) ← √(u²) = │u│for all real numbers u
4 = │x+2│
±4 = x+2 ← If │u│=a, then u = ±a
-2 ± 4 = x
2, -6 = x ← ANSWER
➌ 4² = (x+2)² ... Expand
16 = x² + 4x + 4
0 = x² + 4x - 12
0 = (x+6)(x-2)
x= -6, x=2 ← ANSWER
——————————————————————————————————————
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4^2 = (x + 2)^2
sqrt(4^2) = sqrt[(x + 2)^2]
+/- 4 = x + 2
x = 4 - 2 and x = - 4 - 2
x = 2 and x = - 6
----------------------------
OR
4^2 = (x + 2)^2
16 = 4^2 = (x + 2)^2 = x^2 + 4x + 4
x^2 + 4x - 12 = 0
(x + 6).(x - 2) = 0
x + 6 = 0 or x - 2 = 0
x = - 6 or x = 2
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Hope this helps!
sqrt(4^2) = sqrt[(x + 2)^2]
+/- 4 = x + 2
x = 4 - 2 and x = - 4 - 2
x = 2 and x = - 6
----------------------------
OR
4^2 = (x + 2)^2
16 = 4^2 = (x + 2)^2 = x^2 + 4x + 4
x^2 + 4x - 12 = 0
(x + 6).(x - 2) = 0
x + 6 = 0 or x - 2 = 0
x = - 6 or x = 2
---------------------------
Hope this helps!
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Since both sides are raised to the 2 power, you can just cancel those out... then 4 = (x+2) and x=2
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16 = (x+2)^2
Square root both sides:
4 = x + 2
x = 2
Square root both sides:
4 = x + 2
x = 2
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x + 2 = +/- 4 => x = 2, -6