Question

if a=1,b= -2,c=-1, show that 7a+b+c=2abc​

Answer 1

Left hand side

7+a+b+c = 7+1-2-1

= 5

Right hand side

2abc = 2×1×-2×-1

= 4

Hence the question is invalid.

Answer 2

to show that the equation is true or not just put the values of the given variables in the equation.

a = 1

b = -2

c = -1

$7a + b + c = 2abc$

7×1+(-2)+(-1) = 2×1×(-2)×(-1)

7-2-1 = 2×2

7-3 = 4

4=4

hence proved