If `0.2x =10-0.5y,` then `10y+4x=`
`1/2x - 2.3 y =7`
`ax -8y=-1`

0.4 x + 0.3 y = 1.7 , 0.7 x - 0.2 y = 0.8

Solve using the method of substitution. ( i) 2x-3y =7,5x +y=9 (ii) 1.5x+ 0.1 y =6.2,3x -0.4y=11.2 (iii) 10% of x +20% of y =24, 3x-y=20 (iv) sqrt2x -sqrt 3y =1, sqrt 3x -sqrt 8y =0

{:(0.4x + 0.3y = 1.7),(0.7x - 0.2y = 0.8):}

{:(0.4x + 0.3y = 1.7),(0.7x - 0.2y = 0.8):}

(i) Z = 20x + 10y x + 2y le 28, 3x + y le 24, x ge 2, x, y ge 0 (ii) Z = 7x + 10y 4x + 6y le 240, 6x + 3y le 240, x ge 10, x ge 0, y ge 0 (iii) Z = 22x + 44y subject to the constraints: x + y ge 3, 3x + 8y le 24, x - y ge 0, x, y ge 0 .

On comparing the ratios (a_1)/(a_2),(b_1)/(b_2) and (c_1)/(c_2) , find out whether the following pair of linear equations are consistent, or inconsistent. (i) 3x+2y=5; 2x-3y = 7 (ii) 2x-3y=8 ; 4x-y=9 (iii) 3/2x+5/3y=7 ; 9x-10y=14 (iv) 5x-3y=11 ; -10x+6y = -22 (v) 4/3 x +2y=8 ; 2x+3y = 12

If 2[3 4 5x]+[1y0 1]=[7 0 10 5] , find x and y .

The equation of the ellipse whose focus is (1, -1) , directrix is the line x-y-3=0 and eccentricity is 1/2 , is: (A) 7x^2 + 2xy + 7y^2 + 7 = 0 (B) 7x^2 + 2xy+7y^2 + 10x - 10y - 7 = 0 (C) 7x^2 + 2xy + 7y^2 - 10x + 10y + 7 = 0 (D) none of these