Question

If 2z - 1/3z = 1 , find the value of :
1) 2z + 1/3z. 2) 4z^2 + 1/9z^2. 3) 4z^2 - 1/9z^2. ​

Answer 1

Answer:

2z - 1/3z = 1

(6z-z)/3 = 1

5z = 3

z = 3/5

1) 2z+1/3z = 2×3/5 + (1×3)/(3×5) = 6/5 + 3/15 = 6/5 + 1/5 = 7/5

2) 4$z^{2}$ + 1/9 z^2

z^2 = (3/5)^2 = 9/25

therefore,

4×9/25 + 1/9 ×9/25 = (36+1)/25 = 37/25

3) 4 ×9/25 - (1/9 × 9/25) = (36-1)/25 = 35/25= 7/5