Question

Решите уравнение и выполните проверку. а) -20*( х-13) = -220 б) (30 - 7х) * 8 = 352 в) 5/12у - 3/4 = 1/2

Answer 1

а) -20*( х-13) = -220

-20х+260=-220

-20х=-220-260

-20х=-480

х=-480/(-20)

х=24

Проверка: -20*(24-13)=-220

                  -20*11=-220

                    -220=-220

б) (30 - 7х) * 8 = 352

240-56х=352

-56х=352-240

-56х=112

х=112/(-56)

х=-2

Проверим: (30-7*(-2))*8=352

                     (30+14)*8=352

                      44*8=352

                       352=352

в) 5/12у - 3/4 = 1/2

5/12у=1/2+3/4

5/12у=5/4

у=5/4:5/12

у=3

Проверим: 5/12*3-3/4=1/2

                    15/12-3/4=1/2

                    15/12-9/12=1/2

                     6/12=1/2

                      1/2=1/2

Answer 2

а) -20*( х-13) = -220

-20x+260=-220

-20x=-480

x=-480/(-20)

x=24.

Проверка

-20*(24-13)=-220

б) (30 - 7х) * 8 = 352

240-56x=352

-56x=112

x=112/(-56)

x=-2

Проверка

(30 + 14) * 8 = 352

в) 5/12у - 3/4 = 1/2

5/12у=1/2+3/4

5/12у=5/4

у=5/4:5/12

у=3

Проверка:

15/12-3/4=1/2

15/12-9/12=1/2

6/12=1/2