Question

Solve the following equations by elimination method:

(i) x/



+





= 2;





–





=





(ii) x – 2 y + 1 = 0; 4 x + 3 y = 18

(iii) 0.4x + 0.3y = 1.7; 0.7x – 0.2y = 0.8; (iv) 7(y + 3) – 2(x + 2) = 14; 4(y – 2) + 3(x – 3) = 2

(v)



+





= 11;





–





= –7​

Answer 1

Step-by-step explanation:

(ii) x – 2 y + 1 = 0; 4 x + 3 y = 18

x-2y= -1 ---------1

4x+3y=18. ----------2

Multiplying equation 1 by 4

4×x-4×2y=4× -1

4x-8y= -4. ----------3

Substracting equation 3 from 2

4x+3y=18

-. 4x-8y= -4

(-). (+). (+)

11y= 22

y = 22/11

y = 2

Substituting y=2 in equation 1

x-2y=-1

x-2×2=-1

x-4=-1

x=-1+4

x=3

(x,y)=(2,3)