Question

Let a, b, c be are real number such that a-7b=4 and 8a+4b-c=7 find the value of a ^2-b^2+c^2​

Answer 1

Answer:

#HelloDear!!

Step-by-step explanation:

Rearrange the ewuationto become

a + 8c = 4 + 7b and 8a - c = 7 -4b

Now square both equation to get,

a^2 + 16ac + 64c^2 = 16 + 56b + 49b^2 and

64a^2 - 16ac + c^2 = 16b^2 - 56b + 49

Adding two equation,

65a^2 + 65c^2 = 65b^2 + 65.

So,

By, Using the Formula,

a^2 - b^2 + c^2

65a^2 - 65b^2 + 65c^2 = 65