Question

Tìm x, biết:

a) 3,2.x + (-1,2).x + 2.7 = -4,9 b) -5,6.x + 2,9.x - 3,86 = -9,8

Answer 1

a, \(3,2x+\left(-1,2\right)x+2,7=-4,9\)

\(\)\(\left[3,2+\left(-1,2\right)\right]x=\left(-4,9\right)-2,7\\ 2x=-7,6\\ x=-7,6:2=-3,8\)

b,

\(-5,6x+2,9x-3,86=-9,8\\ \left[\left(-5,6\right)+2,9\right]x=-9,8+3,86\\ -2,7x=-5,94\\ x=-5,94:\left(-2,7\right)=2,2\)

Answer 2

a. \(3,2.x+\left(-1,2\right).x+2,7=-4,9\)

\(\Rightarrow2x=-4,9-2,7=-7,6\)

\(\Rightarrow x=-7,6:2=-3,8\)

Vậy.........

b. \(-5,6.x+2,9.x-3,86=-9,8\)

\(\Rightarrow-2,7.x=-9,8+3,86=-5,94\)

\(\Rightarrow x=-5,94:\left(-2,7\right)=2,2\)

Vậy.............