Tìm x, biết: a, -x + 7/4 = 6/5 - 3/4 b, 1-2x= 9/8 + 7/5 : 2/5

a) –x + 74=65−34

-x + 74 = 2420−1520

-x + 74 = 920

-x = 920−74

-x = 920−3520

-x = −2620=−1310

x = 1310

Vậy x = 1310.

b) 1 – 2x = 98+75:25

1 – 2x = 98+75.52

1 – 2x = 98+72

1 – 2x = 98+288

1 – 2x = 378

2x = 1 – 378

2x = 88−378

2x = −298

x = −298 : 2

x = −2916

Vậy x = −2916