tìm x
a, x * 2 + x * 3 = 4
..............................
..................................
..................................
.....................................
b, x * 9 - 1,5 = 30
...........................
................................
..............................
................................
a,\(x.2+x.3=4\\\) b,\(x.9-1,5=30\)
\(x\left(2+3\right)=4\) \(x.9=30+1,5=31,5\)
\(x=31,5:9=3,5\)
\(x.5=4=>x=4:5=\frac{4}{5}\)
a, x * 2 + x * 3 = 4
x * ( 2 + 3 ) = 4
x * 5 = 4
x = 4 : 5
x = 4/5
b, x * 9 - 1,5 = 30
x * 9 = 30 + 1,5
x * 9 = 31,5
x = 31,5 : 9
x = 3,5
a, x * 2 + x * 3 = 4
x * ( 2 + 3 ) = 4
x * 5 = 4
x = 4:5
x = \(\frac{4}{5}\)
b, x* 9 - 1,5 = 30
x* 9 = 30 + 1,5
x* 9 = 31,5
x = 31,5 : 9
x = \(\frac{7}{2}\)
a) \(x.2+x.3=4\)
\(\Leftrightarrow x.\left(2+3\right)=4\)
\(\Leftrightarrow x.5=4\)
\(\Leftrightarrow x=4:5\)
\(\Leftrightarrow x=0,8\)
Vậy x = 0,8
b) \(x.9-1,5=30\)
\(\Leftrightarrow x.9=30+1,5\)
\(\Leftrightarrow x.9=31,5\)
\(\Leftrightarrow x=31,5:9\)
\(\Leftrightarrow x=3,5\)
Vậy x = 3,5
_Chúc bạn học tốt_