展开 (sqrt(x+5)-3)(sqrt(x^2+9)+5)

解答

展开

(x + 5 - 3) (x^{2} + 9 + 5)

x^{3} + 9 x + 5 x^{2} + 45 + 5 x + 5 - 3 x^{2} + 9 - 15

求解步骤

(x + 5 - 3) (x^{2} + 9 + 5)

Apply FOIL method

(x + 5 - 3) (x^{2} + 9 + 5) : x^{3} + 9 x + 5 x^{2} + 45 + 5 x + 5 - 3 x^{2} + 9 - 15

= x^{3} + 9 x + 5 x^{2} + 45 + 5 x + 5 - 3 x^{2} + 9 - 15

s im pl i f y (1 + 2 y i)^{2}

e x p an d \frac{( k + 1 ) ^{4} ( k + 2 ) ( k + 3 )}{3}

e x p an d \frac{11 s ^{2} - 2 s + 5}{( s - 2 ) ( 2 s - 1 ) ( s + 1 )}

e x p an d (a + b) cos (c) + (a + c) cos (b) + (b + c) cos (a)

e x p an d \frac{5}{( 4 + x ) ^{2}}