Question

3. The value of x in 3/4 x = 7 - x
is
7
4
ОО
1
З​

Answer 1

answer :

4

explanation:

3x=28 - 4x

3x+4x =24

7x=24

devide both sides by 7

x=4

Answer 2

Ans : 6.38 & 0.12

3/4 x = 7 - x

3/4 = x(7 - x)

3/4 = 7x - x2

3 = 4(7x - x2)

3 = 28x - 4x2

4x2 - 28x + 3 = 0

a = 4, b = -28 & c = 3 (from the above equation)

x = -b +-√b2 - 4ac/ 2a

x = -(-28) +-√(-28)2 - 4×4×3 / 2×4

= 28 +-√784 - 48 / 8

= 28 +- √736 / 8

= 13 +-√157 / 4

= 13 + 12.52 / 4 & 13 - 12.52 / 4

= 25.52 / 4 & 0.48 / 4

= 6.38 & 0.12