Use direct method to evaluate : (i) (x + 1)(x - 1) (ii) (2 + a)(2 - a)

1.	Use direct method to evaluate : (i) (x + 1)(x - 1) (ii) (2 + a)(2 - a) (iii) (3b - 1)(3b + 1) (iv) ( 4 + 5x)(4 - 5x) (v) (2a + 3)(2a - 3) (vi) (xy + 4)(xy - 4) (vii) (ab + x^2)(ab - x^2) (viii) (3x^2 + 5y^2)(3x^2 - 5y^2) (vi) (xy + 4)(xy - 4) (ix) (z−23)(z+23) (x) (35a+12)(35a−12) (xi) (0.5 - 2a)(0.5 + 2a) (xii) (a2−b2)(a2+b3)
Answer» Use direct method to evaluate : (i) (x + 1)(x - 1) (ii) (2 + a)(2 - a) (iii) (3b - 1)(3b + 1) (iv) ( 4 + 5x)(4 - 5x) (v) (2a + 3)(2a - 3) (vi) (xy + 4)(xy - 4) (vii) (ab + x^2)(ab - x^2) (viii) (3x^2 + 5y^2)(3x^2 - 5y^2) (vi) (xy + 4)(xy - 4) (ix) $(z - \frac{2}{3}) (z + \frac{2}{3})$ (x) $(\frac{3}{5} a + \frac{1}{2}) (\frac{3}{5} a - \frac{1}{2})$ (xi) (0.5 - 2a)(0.5 + 2a) (xii) $(\frac{a}{2} - \frac{b}{2}) (\frac{a}{2} + \frac{b}{3})$

Use direct method to evaluate : (i) (x + 1)(x - 1) (ii) (2 + a)(2 - a) (iii) (3b - 1)(3b + 1) (iv) ( 4 + 5x)(4 - 5x) (v) (2a + 3)(2a - 3) (vi) (xy + 4)(xy - 4) (vii) (ab + x^2)(ab - x^2) (viii) (3x^2 + 5y^2)(3x^2 - 5y^2) (vi) (xy + 4)(xy - 4) (ix) (z−23)(z+23) (x) (35a+12)(35a−12) (xi) (0.5 - 2a)(0.5 + 2a) (xii) (a2−b2)(a2+b3)

Answer»

Use direct method to evaluate :

(i) (x + 1)(x - 1)

(ii) (2 + a)(2 - a)

(iii) (3b - 1)(3b + 1)

(iv) ( 4 + 5x)(4 - 5x)

(v) (2a + 3)(2a - 3)

(vi) (xy + 4)(xy - 4)

(vii) (ab + x^2)(ab - x^2)

(viii) (3x^2 + 5y^2)(3x^2 - 5y^2)

(vi) (xy + 4)(xy - 4)

(ix) $(z - \frac{2}{3}) (z + \frac{2}{3})$

(x) $(\frac{3}{5} a + \frac{1}{2}) (\frac{3}{5} a - \frac{1}{2})$

(xi) (0.5 - 2a)(0.5 + 2a)

(xii) $(\frac{a}{2} - \frac{b}{2}) (\frac{a}{2} + \frac{b}{3})$