If a + b + c = 6, a3 + b3 + c3 - 3abc = 342, then what is the value of ab + bc + ca?
A. 5
B. 8
C. -7
D. -5
Answer: Option C
Solution(By Examveda Team)
Let c = 0a + b = 6
a3 + b3 = 342
ab = ?
(a3 + b3) = (a + b)[(a + b)2 - 3ab]
342 = 6[62 - 3ab]
57 = 36 - 3ab
3ab = -21
ab = -7
Related Questions on Algebra
If $$p \times q = p + q + \frac{p}{q}{\text{,}}$$ then the value of 8 × 2 is?
A. 6
B. 10
C. 14
D. 16
A. $$1 + \frac{1}{{x + 4}}$$
B. x + 4
C. $$\frac{1}{x}$$
D. $$\frac{{x + 4}}{x}$$
A. $$\frac{{20}}{{27}}$$
B. $$\frac{{27}}{{20}}$$
C. $$\frac{6}{8}$$
D. $$\frac{8}{6}$$
Join The Discussion