Question

Algebra 15m+17n=21 ,17m+15n=11

Answer 1

Step-by-step explanation:

(a + b) 2 = a 2 + b 2 + 2ab

(a − b) 2 = a 2 + b 2 − 2ab

a 2 − b 2 = (a − b) (a + b)

(x + a) (x + b) = x 2 + (a + b) x + ab

(a + b + c) 2 = a 2 + b 2 + c 2 + 2ab + 2bc + 2ca

(a + (−b) + (−c)) 2 = a 2 + (−b) 2 + (−c) 2 + 2a (−b) + 2 (−b) (−c) + 2a (−c)

(a – b – c) 2 = a 2 + b 2 + c 2 − 2ab + 2bc − 2ca

(a + b) 3 = a 3 + b 3 + 3ab(a + b)

(a − b) 3 = a 3 - b 3 - 3ab(a - b)

a 3 − b 3 = (a − b) (a 2 + b 2 + ab)

a 3 + b 3 = (a + b) (a 2 + b 2 − ab)

(a + b + c) 3 = a 3 + b 3 + c 3 + 3(a + b)(b + c)(c + a)

a 3 + b 3 + c 3 − 3abc = (a + b + c) (a 2 + b 2 + c 2 − ab − bc − ac)

If (a + b + c) = 0,

a 3 + b 3 + c 3 = 3abc

Answer 2

Answer:

15m+17n=21

17m+15n=11

(15+17)(m+n)=21+11

32(m+n)=32

m+n =32/32

m+n = 1

this is spcl case of linear equation in two variable ..

general formula is

ax+by=c1

bx+ay=c2 .. then ,

(a+b)(x+y)=c1+c2