a) 5(x + 35) = 515
x + 35 = 515 : 5
x + 35 = 103
x = 103 - 35
x = 68
b) 12x - 33 = 32.33
12x - 33 = 35
12x - 33 = 243
12x = 243 + 33
12x = 276
x = 276 : 12
x = 23
c) 541 + (218 - x) = 73
218 - x = 73 - 541
218 - x = -468
-x = -468 - 218
-x = -686
x = 686
d) 1230 : 3(x - 20) = 10
410(x - 20) = 10
x - 20 = 10 : 410
x - 20 = 1/41
x = 1/41 + 20
x = 821/41
5(x+ 35 ) = 515
x + 35 = 103
x = 68
12x - 33 = 32 . 33
12x = 276
x = 23
541 + ( 218 - x ) = 73
218 - x = - 468
x = - 250
1230 : 3( x - 20 ) = 10
=> 3x - 60 = 123
=> 3x = 183
=> x = 61
Study well
a) \(5\left(x+35\right)=515\)
\(\left(x+35\right)=515:5\)
\(x+35=103\)
\(x=103-35\)
\(x=68\)
Vậy \(x=68\)
b) \(12x.-33=3^2.3^3\)
\(12x.-33=9.27\)
\(12x.-33=243\)
\(12.x=243+33\)
\(12.x=276\)
\(x=276:12\)
\(x=23\)
Vậy \(x=23\)
c) \(541+\left(218-x\right)=73\)
\(\left(218-x\right)=73-541\)
\(218-x=-468\)
\(x=218-\left(-468\right)\)
\(x=218+468\)
\(x=686\)
Vậy \(x=686\)
d) \(1230:3\left(x-20\right)=10\)
\(3.\left(x-20\right)=1230:10\)
\(3.\left(x-20\right)=123\)
\(\left(x-20\right)=123:3\)
\(x-20=41\)
\(x=41+20\)
\(x=61\)
Vậy \(x=61\)
Chúc bạn học tốt !!!
