a)82-x*5=86-9
82-x*5=77
x*5=82-77
x*5=5
x=5/5
x=1
a ) 83 - x X 5 = 86 - 9
83 - x X 5 = 77
x X 5 = 83 - 77
x X 5 = 6
x = 6 : 5
x = 1,2
b ) 78 - x + x + x + x = 4 x 7
78 + x + x = 4 x 7
78 + x + x = 28
2 X x = 28 - 78
2 X x = - 50
x = - 50 : 2
x = - 25
82—x.5=86—9
82—x.5=75
x.5=82—75
x.5=7
x=7:5
x=7/5
78—x+x+x+x=4.7
78—x.4=28
x.4=78—28
x.4=50
x=50:4
x=1,25
SR au viết nhầm phần a )
82 - x X 5 = 86 - 9
82 - x X 5 = 77
x X 5 = 77 - 82
x X 5 = 5
x = 5 : 5
x = 1
nguyen tai nhat the
a) \(82-x\cdot5=86-9\)
\(82-x\cdot5=77\)
\(x\cdot5=82-77\)
\(x\cdot5=5\)
\(\Rightarrow x=1\)
a) \(82-5x=86-9\)
\(\Leftrightarrow82-5x=77\)
\(\Leftrightarrow5x=5\)
\(\Leftrightarrow x=1\)
b) \(78-x+x+x+x=4\cdot7\)
\(\Leftrightarrow78+2x=28\)
\(\Leftrightarrow2x=-50\)
\(\Leftrightarrow x=-25\)
nguyen tai nhat the
\(78-x+x+x+x=4\cdot7\)
\(78+x+x=4\cdot7\)
\(78+x+x=28\)
\(2\times x=28-78\)
\(2\times x=-50\)
\(x=-50\div2\)
\(x=-25\)