Question

Solve each of the following equations for x. (a) 5x-7=28 (b) 12-5x= x+30 (c) 5(x+2)= 1-3x

Зx-y=-5 X+2y=3

Answer 1

(a) 7

(b) -3

(c)
`-(9)/(8)`

(d) -1

Explanation:

(a) 5x - 7 = 28

5x = 28 + 7

5x = 35

⇒ x = 7

(b) 12 - 5x = x + 30

-5x = x + 30 - 12

-5x = x + 18

-5x - x = 18

-6x = 18

⇒ x = -3

(c) 5(x+2) = 1 - 3x

5x + 10 = 1 - 3x

5x = 1 - 3x - 10

5x + 3x = -9

8x = -9

⇒ x =
`-(9)/(8)`,

(d) Given system of equations,

Зx-y = -5 ------(1),

x + 2y = 3 ----(2),

Equation (2) + 2 equation (1),

x + 6x = 3 - 10⇒ 7x = -7 ⇒ x = -1