a)125 : x = 22 - (-1)
125 : x = 4 + 1
125 : x = 5
x = 125 : 5
x = 25
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b) 2x - 8 = -4
2x = (-4) + 8
2x = 4
x = 4 : 2
x = 2
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c) Xem lại đề.
\(125:x=2^2-\left(-1\right)\)
\(=>125:x=4+1\)
\(=>125:x=5\)
\(=>x=125:5\)
\(=>x=25\)
_____
\(2x-8=-4\)
\(=>2x=\left(-4\right)+8\)
\(=>2x=4\)
\(=>x=4:2\)
\(=>x=2\)
_______
\(6^{2x+5}=216\)
\(=>6^{2x+5}=6^3\)
\(=>2x+5=3\)
\(=>2x=3-5\)
\(=>2x=-2\)
\(=>x=\left(-2\right):2\)
\(=>x=-1\)
\(#NqHahh\)
125:x=22 - (-1)
125:x=4+1
125:x=5
X=125:5
X=25
2x -8 = -4
2x=-4+8
2x=4
X=4:2
X=2
62(x+5) = 216
36(x+5) = 216
X+5 = 216:36
X+5=6
X=6-5
X=1