what is the algebraic expression for 7 less than 9

121x 2 - 25y 2 = (11x) 2 - (5y) 2 = (11x + 5y) (11x - 5y) [Using the identity a 2 -b 2 =(a-b)(a+b)] Factorise: (5a + 6b) 2 - 49b 2 Let x = 5a + 6b Then the given expression = (x) 2 - (7b) 2 = (x + 7b) (x - 7b) Re-substituting the value of x, we..

Find at least 3 sets of values for the variables satisfying the equation. 2x+y=5 Express y in terms of x. y=5-2x Select three values of x, find corresponding values of y. x=0, y=5-(2x0)=5 x=1, y=5-(2x1)=3 x=-1, y=5-(-2)=7 Draw the x and y - axes. Choose a suitable scale so ..

= d Number of sides of a polygon = n the required formula is = d = n -3 The sum of the reciprocal of x and the reciprocal of y equals the reciprocal of m. Express this as a formula. Reciprocal of Reciprocal of Reciprocal of The required formula ..

(5y) + (5y) 2 = x 2 - 10xy + 25y 2 Find algebraically the value of 205 2 . 205 2 = (200 + 5) 2 = (200) 2 + 2 (200) (5) + (5) 2 = 40000 + 2000 + 25 = 42025 If the expression 36x 2 + Kx + 25 is a perfect square, find K. Middle term of the given expression..

10} R = {(7, 21), (8, 24), (9, 27), (10, 30)} Domain = {7, 8, 9, 10} and Range = {21, 24, 27, 30} Given A = {3, 4, 5}, R = {(x, y) A x A : x = y - 1} (i) List the ordered pairs of R. (ii) List the elements of the domain of R. (iii) List the elements of the ra..

x 2 - 2x - 48 = x 2 - 8x + 6x - 48 = x(x - 8) + 6(x - 8) = (x - 8) (x + 6) When the coefficient of the highest power is not unity. i.e., type ax 2 bx c, when and b and c are integers. Multiply (3x + 2) (x + 4) and consider the result so obtained. = 3x (x + 4) +2 (x + 4) = 3x 2 + 12x..

Question: Solve the following equation: Answer: 5(3x+5) = 2(2x-1) (by cross-multiplication) 15x-4x = -2-25 11x = -27 ..

Factorise 64a 6 - 343. 64a 6 - 343 = (4a 2 ) 3 - (7) 3 = (4a 2 - 7) (16a 4 + 28a 2 + ..

Study the following equations: a) 4x + 2 = 14 b) x - 7 = 5 - 2x c) 3a - 8 = a + 12 The equation 4x + 2 = 14 is true only when x = 3, Similarly, x - 7 = 5 - 2x is true only when x = 4, and 3a - 8 = a + 23 is true only when a = 10. The two expressions (LHS and RHS) are e..

Identical equations or Identities - Now study the equations given below: a) x + 3 + x + 4 = 2x + 7 2x + 7 = 2x + 7 (By simplification) [ \ any value given to 'x' always satisfies the equation] Similarly, b) (3a + 4) + 2 (a - 1) = 5a + 2 i.e., 5a + 2 = 5a + 2 (By simpli..