Пошаговое объяснение:
1) 7(x+6)=49
x+6=49:7
x+6=7
x=7-6
x=1
проверка
7(x+6) = 7*(1+6)=7*7=49 - верно
15(x-10) = 255
x-10 = 255:15
x-10 = 17
x = 17+10
x = 27
15*(x-10) = 15*(27-10) = 15*17 = 255 - верно
27(19-x) = 324
19-x = 324:27
19-x = 12
x = 19-12
x = 7
27*(19-x) = 27*(19-7) = 27*12 = 324 - верно
2) 3(2x-9) = 27
2x-9 = 27:3
2x-9 = 9
2x = 9+9
2x=18
x = 18:2
x = 9
3*(2x-9) = 3*(2*9 - 9) = 3*(18-9) = 3*9 = 27 - верно
9(5x+8) = 207
5x+8 = 207:9
5x+8 = 23
5x = 23-8
5x = 15
x = 15:5
x = 3
9*(5x+8) = 9*(5*3+8) = 9*(15+8) = 9*23 = 207 - верно
19(39-2x) = 703
39-2x = 703:19
39-2x = 37
2x = 39-37
2x = 2
x = 2:2
x = 1
19*(39-2x) = 19*(39-2*1) = 19*(39-2) = 19*37 = 703 - верно
Пошаговое объяснение:
1) 7(x+6)=49
x+6=49:7
x+6=7
x=7-6
x=1
проверка
7(x+6) = 7*(1+6)=7*7=49 - верно
15(x-10) = 255
x-10 = 255:15
x-10 = 17
x = 17+10
x = 27
проверка
15*(x-10) = 15*(27-10) = 15*17 = 255 - верно
27(19-x) = 324
19-x = 324:27
19-x = 12
x = 19-12
x = 7
проверка
27*(19-x) = 27*(19-7) = 27*12 = 324 - верно
2) 3(2x-9) = 27
2x-9 = 27:3
2x-9 = 9
2x = 9+9
2x=18
x = 18:2
x = 9
проверка
3*(2x-9) = 3*(2*9 - 9) = 3*(18-9) = 3*9 = 27 - верно
9(5x+8) = 207
5x+8 = 207:9
5x+8 = 23
5x = 23-8
5x = 15
x = 15:5
x = 3
проверка
9*(5x+8) = 9*(5*3+8) = 9*(15+8) = 9*23 = 207 - верно
19(39-2x) = 703
39-2x = 703:19
39-2x = 37
2x = 39-37
2x = 2
x = 2:2
x = 1
проверка
19*(39-2x) = 19*(39-2*1) = 19*(39-2) = 19*37 = 703 - верно