Question

решить (3х+7)-(7х+9)=8

Answer 1

(3х+7)-(7х+9)=8
3х+7-7х-9=8
-4х-2=8
-4х=8+2
-4х=10
х=10:(-4)
х= -2,5

Answer 2

$(3x + 7) - (7x + 9) = 8 \\ 3x + 7 - 7x - 9 = 8 \\ 3x - 7x = 8 + 9 - 7 \\ - 4x = 10 \\ x = 10 \div ( - 4) \\ x = - 2.5$