1) 4x2 +12xy +9y2 ; x = -2, y = 2 2) 4/25m2 -mn + 25/16n2 ; m = 5, - Maths - Algebraic Expressions and Identities

Question

1) 4x2 +12xy +9y2 ; x = -2, y = 2
2) 4/25m2 -mn + 25/16n2 ; m = 5, n = 8

Vinay Kumar Sharma · Accepted Answer

1) 4x2 +12xy +9y2 ; x = -2, y = 2 Solution: putting x=-2 and y=2, we get $4 x^{2} + 12 x y + 9 y^{2} = 4 {(- 2)}^{2} + 12 (- 2) (2) + 9 {(2)}^{2} = 4 (4) - 48 + 9 (4) {({- x}^{2} = x^{2})} = 16 - 48 + 36 = 4$ 2) 4/25m2 -mn + 25/16n2 ; m = 5, n = 8 Solution: putting m=5 and n=8,we get $\frac{4}{25} m^{2} - m n + \frac{25}{16} m^{2} = \frac{4}{25} (5^{2}) - (5) (8) + \frac{25}{16} (8^{2}) = \frac{4}{25} (25) - 40 + \frac{25}{16} (64) = 4 - 40 + 100 = 64$

1) 4x2 +12xy +9y2 ; x = -2, y = 2 2) 4/25m2 -mn + 25/16n2 ; m = 5, n = 8

1) 4x² +12xy +9y²; x = -2, y = 2

2) 4/25m²-mn + 25/16n² ; m = 5, n = 8